/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)nfs_vnops.c 8.16 (Berkeley) 5/27/95
 * $FreeBSD: src/sys/nfs/nfs_vnops.c,v 1.150.2.5 2001/12/20 19:56:28 dillon Exp $
 */


/*
 * vnode op calls for Sun NFS version 2 and 3
 */

#include "opt_inet.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/resourcevar.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/namei.h>
#include <sys/nlookup.h>
#include <sys/socket.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#include <sys/fcntl.h>
#include <sys/lockf.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/conf.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>

#include <sys/buf2.h>

#include <vfs/fifofs/fifo.h>
#include <vfs/ufs/dir.h>

#undef DIRBLKSIZ

#include "rpcv2.h"
#include "nfsproto.h"
#include "nfs.h"
#include "nfsmount.h"
#include "nfsnode.h"
#include "xdr_subs.h"
#include "nfsm_subs.h"

#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_var.h>

/* Defs */
#define TRUE    1
#define FALSE   0

static int      nfsfifo_read (struct vop_read_args *);
static int      nfsfifo_write (struct vop_write_args *);
static int      nfsfifo_close (struct vop_close_args *);
static int      nfs_setattrrpc (struct vnode *,struct vattr *,struct ucred *,struct thread *);
static  int     nfs_lookup (struct vop_old_lookup_args *);
static  int     nfs_create (struct vop_old_create_args *);
static  int     nfs_mknod (struct vop_old_mknod_args *);
static  int     nfs_open (struct vop_open_args *);
static  int     nfs_close (struct vop_close_args *);
static  int     nfs_access (struct vop_access_args *);
static  int     nfs_getattr (struct vop_getattr_args *);
static  int     nfs_setattr (struct vop_setattr_args *);
static  int     nfs_read (struct vop_read_args *);
static  int     nfs_fsync (struct vop_fsync_args *);
static  int     nfs_remove (struct vop_old_remove_args *);
static  int     nfs_link (struct vop_old_link_args *);
static  int     nfs_rename (struct vop_old_rename_args *);
static  int     nfs_mkdir (struct vop_old_mkdir_args *);
static  int     nfs_rmdir (struct vop_old_rmdir_args *);
static  int     nfs_symlink (struct vop_old_symlink_args *);
static  int     nfs_readdir (struct vop_readdir_args *);
static  int     nfs_bmap (struct vop_bmap_args *);
static  int     nfs_strategy (struct vop_strategy_args *);
static  int     nfs_lookitup (struct vnode *, const char *, int,
                        struct ucred *, struct thread *, struct nfsnode **);
static  int     nfs_sillyrename (struct vnode *,struct vnode *,struct componentname *);
static int      nfs_laccess (struct vop_access_args *);
static int      nfs_readlink (struct vop_readlink_args *);
static int      nfs_print (struct vop_print_args *);
static int      nfs_advlock (struct vop_advlock_args *);
static int      nfs_kqfilter (struct vop_kqfilter_args *ap);

static  int     nfs_nresolve (struct vop_nresolve_args *);
/*
 * Global vfs data structures for nfs
 */
struct vop_ops nfsv2_vnode_vops = {
        .vop_default =          vop_defaultop,
        .vop_access =           nfs_access,
        .vop_advlock =          nfs_advlock,
        .vop_bmap =             nfs_bmap,
        .vop_close =            nfs_close,
        .vop_old_create =       nfs_create,
        .vop_fsync =            nfs_fsync,
        .vop_getattr =          nfs_getattr,
        .vop_getpages =         vop_stdgetpages,
        .vop_putpages =         vop_stdputpages,
        .vop_inactive =         nfs_inactive,
        .vop_old_link =         nfs_link,
        .vop_old_lookup =       nfs_lookup,
        .vop_old_mkdir =        nfs_mkdir,
        .vop_old_mknod =        nfs_mknod,
        .vop_open =             nfs_open,
        .vop_print =            nfs_print,
        .vop_read =             nfs_read,
        .vop_readdir =          nfs_readdir,
        .vop_readlink =         nfs_readlink,
        .vop_reclaim =          nfs_reclaim,
        .vop_old_remove =       nfs_remove,
        .vop_old_rename =       nfs_rename,
        .vop_old_rmdir =        nfs_rmdir,
        .vop_setattr =          nfs_setattr,
        .vop_strategy =         nfs_strategy,
        .vop_old_symlink =      nfs_symlink,
        .vop_write =            nfs_write,
        .vop_nresolve =         nfs_nresolve,
        .vop_kqfilter =         nfs_kqfilter
};

/*
 * Special device vnode ops
 */
struct vop_ops nfsv2_spec_vops = {
        .vop_default =          vop_defaultop,
        .vop_access =           nfs_laccess,
        .vop_close =            nfs_close,
        .vop_fsync =            nfs_fsync,
        .vop_getattr =          nfs_getattr,
        .vop_inactive =         nfs_inactive,
        .vop_print =            nfs_print,
        .vop_read =             vop_stdnoread,
        .vop_reclaim =          nfs_reclaim,
        .vop_setattr =          nfs_setattr,
        .vop_write =            vop_stdnowrite
};

struct vop_ops nfsv2_fifo_vops = {
        .vop_default =          fifo_vnoperate,
        .vop_access =           nfs_laccess,
        .vop_close =            nfsfifo_close,
        .vop_fsync =            nfs_fsync,
        .vop_getattr =          nfs_getattr,
        .vop_inactive =         nfs_inactive,
        .vop_print =            nfs_print,
        .vop_read =             nfsfifo_read,
        .vop_reclaim =          nfs_reclaim,
        .vop_setattr =          nfs_setattr,
        .vop_write =            nfsfifo_write
};

static int      nfs_mknodrpc (struct vnode *dvp, struct vnode **vpp,
                                  struct componentname *cnp,
                                  struct vattr *vap);
static int      nfs_removerpc (struct vnode *dvp, const char *name,
                                   int namelen,
                                   struct ucred *cred, struct thread *td);
static int      nfs_renamerpc (struct vnode *fdvp, const char *fnameptr,
                                   int fnamelen, struct vnode *tdvp,
                                   const char *tnameptr, int tnamelen,
                                   struct ucred *cred, struct thread *td);
static int      nfs_renameit (struct vnode *sdvp,
                                  struct componentname *scnp,
                                  struct sillyrename *sp);

SYSCTL_DECL(_vfs_nfs);

static int nfs_flush_on_rename = 1;
SYSCTL_INT(_vfs_nfs, OID_AUTO, flush_on_rename, CTLFLAG_RW, 
           &nfs_flush_on_rename, 0, "flush fvp prior to rename");
static int nfs_flush_on_hlink = 0;
SYSCTL_INT(_vfs_nfs, OID_AUTO, flush_on_hlink, CTLFLAG_RW, 
           &nfs_flush_on_hlink, 0, "flush fvp prior to hard link");

static int      nfsaccess_cache_timeout = NFS_DEFATTRTIMO;
SYSCTL_INT(_vfs_nfs, OID_AUTO, access_cache_timeout, CTLFLAG_RW, 
           &nfsaccess_cache_timeout, 0, "NFS ACCESS cache timeout");

static int      nfsneg_cache_timeout = NFS_MINATTRTIMO;
SYSCTL_INT(_vfs_nfs, OID_AUTO, neg_cache_timeout, CTLFLAG_RW, 
           &nfsneg_cache_timeout, 0, "NFS NEGATIVE NAMECACHE timeout");

static int      nfspos_cache_timeout = NFS_MINATTRTIMO;
SYSCTL_INT(_vfs_nfs, OID_AUTO, pos_cache_timeout, CTLFLAG_RW, 
           &nfspos_cache_timeout, 0, "NFS POSITIVE NAMECACHE timeout");

static int      nfsv3_commit_on_close = 0;
SYSCTL_INT(_vfs_nfs, OID_AUTO, nfsv3_commit_on_close, CTLFLAG_RW, 
           &nfsv3_commit_on_close, 0, "write+commit on close, else only write");
#if 0
SYSCTL_INT(_vfs_nfs, OID_AUTO, access_cache_hits, CTLFLAG_RD, 
           &nfsstats.accesscache_hits, 0, "NFS ACCESS cache hit count");

SYSCTL_INT(_vfs_nfs, OID_AUTO, access_cache_misses, CTLFLAG_RD, 
           &nfsstats.accesscache_misses, 0, "NFS ACCESS cache miss count");
#endif

#define NFSV3ACCESS_ALL (NFSV3ACCESS_READ | NFSV3ACCESS_MODIFY          \
                         | NFSV3ACCESS_EXTEND | NFSV3ACCESS_EXECUTE     \
                         | NFSV3ACCESS_DELETE | NFSV3ACCESS_LOOKUP)

static __inline
void
nfs_knote(struct vnode *vp, int flags)
{
        if (flags)
                KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, flags);
}

/*
 * Returns whether a name component is a degenerate '.' or '..'.
 */
static __inline
int
nlcdegenerate(struct nlcomponent *nlc)
{
        if (nlc->nlc_namelen == 1 && nlc->nlc_nameptr[0] == '.')
                return(1);
        if (nlc->nlc_namelen == 2 &&
            nlc->nlc_nameptr[0] == '.' && nlc->nlc_nameptr[1] == '.')
                return(1);
        return(0);
}

static int
nfs3_access_otw(struct vnode *vp, int wmode,
                struct thread *td, struct ucred *cred)
{
        struct nfsnode *np = VTONFS(vp);
        int attrflag;
        int error = 0;
        u_int32_t *tl;
        u_int32_t rmode;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = 1;

        nfsstats.rpccnt[NFSPROC_ACCESS]++;
        nfsm_reqhead(&info, vp, NFSPROC_ACCESS,
                     NFSX_FH(info.v3) + NFSX_UNSIGNED);
        ERROROUT(nfsm_fhtom(&info, vp));
        tl = nfsm_build(&info, NFSX_UNSIGNED);
        *tl = txdr_unsigned(wmode); 
        NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_ACCESS, td, cred, &error));
        ERROROUT(nfsm_postop_attr(&info, vp, &attrflag, NFS_LATTR_NOSHRINK));
        if (error == 0) {
                NULLOUT(tl = nfsm_dissect(&info, NFSX_UNSIGNED));
                rmode = fxdr_unsigned(u_int32_t, *tl);
                np->n_mode = rmode;
                np->n_modeuid = cred->cr_uid;
                np->n_modestamp = mycpu->gd_time_seconds;
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        return error;
}

/*
 * nfs access vnode op.
 * For nfs version 2, just return ok. File accesses may fail later.
 * For nfs version 3, use the access rpc to check accessibility. If file modes
 * are changed on the server, accesses might still fail later.
 *
 * nfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred)
 */
static int
nfs_access(struct vop_access_args *ap)
{
        struct ucred *cred;
        struct ucred *ncred;
        struct ucred *ocred;
        struct vnode *vp = ap->a_vp;
        thread_t td = curthread;
        int error = 0;
        u_int32_t mode, wmode;
        struct nfsnode *np = VTONFS(vp);
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        int v3 = NFS_ISV3(vp);

        lwkt_gettoken(&nmp->nm_token);

        /*
         * Disallow write attempts on filesystems mounted read-only;
         * unless the file is a socket, fifo, or a block or character
         * device resident on the filesystem.
         */
        if ((ap->a_mode & VWRITE) && (vp->v_mount->mnt_flag & MNT_RDONLY)) {
                switch (vp->v_type) {
                case VREG:
                case VDIR:
                case VLNK:
                        lwkt_reltoken(&nmp->nm_token);
                        return (EROFS);
                default:
                        break;
                }
        }

        /*
         * The NFS protocol passes only the effective uid/gid over the wire but
         * we need to check access against real ids if AT_EACCESS not set.
         * Handle this case by cloning the credentials and setting the
         * effective ids to the real ones.
         *
         * The crdup() here can cause a lot of ucred structures to build-up
         * (up to maxvnodes), so do our best to avoid it.
         */
        if (ap->a_flags & AT_EACCESS) {
                cred = crhold(ap->a_cred);
        } else {
                cred = ap->a_cred;
                if (cred->cr_uid == cred->cr_ruid &&
                    cred->cr_gid == cred->cr_rgid) {
                        cred = crhold(ap->a_cred);
                } else {
                        cred = crdup(ap->a_cred);
                        cred->cr_uid = cred->cr_ruid;
                        cred->cr_gid = cred->cr_rgid;
                }
        }

        /*
         * For nfs v3, check to see if we have done this recently, and if
         * so return our cached result instead of making an ACCESS call.
         * If not, do an access rpc, otherwise you are stuck emulating
         * ufs_access() locally using the vattr. This may not be correct,
         * since the server may apply other access criteria such as
         * client uid-->server uid mapping that we do not know about.
         */
        if (v3) {
                if (ap->a_mode & VREAD)
                        mode = NFSV3ACCESS_READ;
                else
                        mode = 0;
                if (vp->v_type != VDIR) {
                        if (ap->a_mode & VWRITE)
                                mode |= (NFSV3ACCESS_MODIFY | NFSV3ACCESS_EXTEND);
                        if (ap->a_mode & VEXEC)
                                mode |= NFSV3ACCESS_EXECUTE;
                } else {
                        if (ap->a_mode & VWRITE)
                                mode |= (NFSV3ACCESS_MODIFY | NFSV3ACCESS_EXTEND |
                                         NFSV3ACCESS_DELETE);
                        if (ap->a_mode & VEXEC)
                                mode |= NFSV3ACCESS_LOOKUP;
                }
                /* XXX safety belt, only make blanket request if caching */
                if (nfsaccess_cache_timeout > 0) {
                        wmode = NFSV3ACCESS_READ | NFSV3ACCESS_MODIFY | 
                                NFSV3ACCESS_EXTEND | NFSV3ACCESS_EXECUTE | 
                                NFSV3ACCESS_DELETE | NFSV3ACCESS_LOOKUP;
                } else {
                        wmode = mode;
                }

                /*
                 * Does our cached result allow us to give a definite yes to
                 * this request?
                 */
                if (np->n_modestamp && 
                   (mycpu->gd_time_seconds < (np->n_modestamp + nfsaccess_cache_timeout)) &&
                   (cred->cr_uid == np->n_modeuid) &&
                   ((np->n_mode & mode) == mode)) {
                        nfsstats.accesscache_hits++;
                } else {
                        /*
                         * Either a no, or a don't know.  Go to the wire.
                         */
                        nfsstats.accesscache_misses++;
                        error = nfs3_access_otw(vp, wmode, td, cred);
                        if (!error) {
                                if ((np->n_mode & mode) != mode) {
                                        error = EACCES;
                                }
                        }
                }
        } else {
                if ((error = nfs_laccess(ap)) != 0) {
                        crfree(cred);
                        lwkt_reltoken(&nmp->nm_token);
                        return (error);
                }

                /*
                 * Attempt to prevent a mapped root from accessing a file
                 * which it shouldn't.  We try to read a byte from the file
                 * if the user is root and the file is not zero length.
                 * After calling nfs_laccess, we should have the correct
                 * file size cached.
                 */
                if (cred->cr_uid == 0 && (ap->a_mode & VREAD)
                    && VTONFS(vp)->n_size > 0) {
                        struct iovec aiov;
                        struct uio auio;
                        char buf[1];

                        aiov.iov_base = buf;
                        aiov.iov_len = 1;
                        auio.uio_iov = &aiov;
                        auio.uio_iovcnt = 1;
                        auio.uio_offset = 0;
                        auio.uio_resid = 1;
                        auio.uio_segflg = UIO_SYSSPACE;
                        auio.uio_rw = UIO_READ;
                        auio.uio_td = td;

                        if (vp->v_type == VREG) {
                                error = nfs_readrpc_uio(vp, &auio);
                        } else if (vp->v_type == VDIR) {
                                char* bp;
                                bp = kmalloc(NFS_DIRBLKSIZ, M_TEMP, M_WAITOK);
                                aiov.iov_base = bp;
                                aiov.iov_len = auio.uio_resid = NFS_DIRBLKSIZ;
                                error = nfs_readdirrpc_uio(vp, &auio);
                                kfree(bp, M_TEMP);
                        } else if (vp->v_type == VLNK) {
                                error = nfs_readlinkrpc_uio(vp, &auio);
                        } else {
                                error = EACCES;
                        }
                }
        }
        /*
         * [re]record creds for reading and/or writing if access
         * was granted.  Assume the NFS server will grant read access
         * for execute requests.
         */
        if (error == 0) {
                if ((ap->a_mode & (VREAD|VEXEC)) &&
                    !nfs_crsame(cred, np->n_rucred)) {
                        ncred = nfs_crhold(cred);
                        ocred = np->n_rucred;
                        np->n_rucred = ncred;
                        if (ocred)
                                crfree(ocred);
                }
                if ((ap->a_mode & VWRITE) &&
                    !nfs_crsame(cred, np->n_wucred)) {
                        ncred = nfs_crhold(cred);
                        ocred = np->n_wucred;
                        np->n_wucred = ncred;
                        if (ocred)
                                crfree(ocred);
                }
        }
        lwkt_reltoken(&nmp->nm_token);
        crfree(cred);

        return(error);
}

/*
 * nfs open vnode op
 * Check to see if the type is ok
 * and that deletion is not in progress.
 * For paged in text files, you will need to flush the page cache
 * if consistency is lost.
 *
 * nfs_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred,
 *          struct file *a_fp)
 */
/* ARGSUSED */
static int
nfs_open(struct vop_open_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        struct vattr vattr;
        struct ucred *ncred;
        struct ucred *ocred;
        int error;

        lwkt_gettoken(&nmp->nm_token);

        if (vp->v_type != VREG && vp->v_type != VDIR && vp->v_type != VLNK) {
#ifdef DIAGNOSTIC
                kprintf("open eacces vtyp=%d\n",vp->v_type);
#endif
                lwkt_reltoken(&nmp->nm_token);
                return (EOPNOTSUPP);
        }

        /*
         * Save valid creds for reading and writing for later RPCs.
         */
        if ((ap->a_mode & FREAD) && !nfs_crsame(ap->a_cred, np->n_rucred)) {
                ncred = nfs_crhold(ap->a_cred);
                ocred = np->n_rucred;
                np->n_rucred = ncred;
                if (ocred)
                        crfree(ocred);
        }
        if ((ap->a_mode & FWRITE) && !nfs_crsame(ap->a_cred, np->n_wucred)) {
                ncred = nfs_crhold(ap->a_cred);
                ocred = np->n_wucred;
                np->n_wucred = ncred;
                if (ocred)
                        crfree(ocred);
        }

        /*
         * Clear the attribute cache only if opening with write access.  It
         * is unclear if we should do this at all here, but we certainly
         * should not clear the cache unconditionally simply because a file
         * is being opened.
         */
        if (ap->a_mode & FWRITE)
                np->n_attrstamp = 0;

        /*
         * For normal NFS, reconcile changes made locally verses 
         * changes made remotely.  Note that VOP_GETATTR only goes
         * to the wire if the cached attribute has timed out or been
         * cleared.
         *
         * If local modifications have been made clear the attribute
         * cache to force an attribute and modified time check.  If
         * GETATTR detects that the file has been changed by someone
         * other then us it will set NRMODIFIED.
         *
         * If we are opening a directory and local changes have been
         * made we have to invalidate the cache in order to ensure
         * that we get the most up-to-date information from the
         * server.  XXX
         */
        if (np->n_flag & NLMODIFIED) {
                np->n_attrstamp = 0;
                if (vp->v_type == VDIR) {
                        error = nfs_vinvalbuf(vp, V_SAVE, 1);
                        if (error == EINTR) {
                                lwkt_reltoken(&nmp->nm_token);
                                return (error);
                        }
                        nfs_invaldir(vp);
                }
        }
        error = VOP_GETATTR(vp, &vattr);
        if (error) {
                lwkt_reltoken(&nmp->nm_token);
                return (error);
        }
        if (np->n_flag & NRMODIFIED) {
                if (vp->v_type == VDIR)
                        nfs_invaldir(vp);
                error = nfs_vinvalbuf(vp, V_SAVE, 1);
                if (error == EINTR) {
                        lwkt_reltoken(&nmp->nm_token);
                        return (error);
                }
                np->n_flag &= ~NRMODIFIED;
        }
        error = vop_stdopen(ap);
        lwkt_reltoken(&nmp->nm_token);

        return error;
}

/*
 * nfs close vnode op
 * What an NFS client should do upon close after writing is a debatable issue.
 * Most NFS clients push delayed writes to the server upon close, basically for
 * two reasons:
 * 1 - So that any write errors may be reported back to the client process
 *     doing the close system call. By far the two most likely errors are
 *     NFSERR_NOSPC and NFSERR_DQUOT to indicate space allocation failure.
 * 2 - To put a worst case upper bound on cache inconsistency between
 *     multiple clients for the file.
 * There is also a consistency problem for Version 2 of the protocol w.r.t.
 * not being able to tell if other clients are writing a file concurrently,
 * since there is no way of knowing if the changed modify time in the reply
 * is only due to the write for this client.
 * (NFS Version 3 provides weak cache consistency data in the reply that
 *  should be sufficient to detect and handle this case.)
 *
 * The current code does the following:
 * for NFS Version 2 - play it safe and flush/invalidate all dirty buffers
 * for NFS Version 3 - flush dirty buffers to the server but don't invalidate
 *                     or commit them (this satisfies 1 and 2 except for the
 *                     case where the server crashes after this close but
 *                     before the commit RPC, which is felt to be "good
 *                     enough". Changing the last argument to nfs_flush() to
 *                     a 1 would force a commit operation, if it is felt a
 *                     commit is necessary now.
 * for NQNFS         - do nothing now, since 2 is dealt with via leases and
 *                     1 should be dealt with via an fsync() system call for
 *                     cases where write errors are important.
 *
 * nfs_close(struct vnode *a_vp, int a_fflag)
 */
/* ARGSUSED */
static int
nfs_close(struct vop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        int error = 0;
        thread_t td = curthread;

        vn_lock(vp, LK_UPGRADE | LK_RETRY); /* XXX */
        lwkt_gettoken(&nmp->nm_token);

        if (vp->v_type == VREG) {
            if (np->n_flag & NLMODIFIED) {
                if (NFS_ISV3(vp)) {
                    /*
                     * Under NFSv3 we have dirty buffers to dispose of.  We
                     * must flush them to the NFS server.  We have the option
                     * of waiting all the way through the commit rpc or just
                     * waiting for the initial write.  The default is to only
                     * wait through the initial write so the data is in the
                     * server's cache, which is roughly similar to the state
                     * a standard disk subsystem leaves the file in on close().
                     *
                     * We cannot clear the NLMODIFIED bit in np->n_flag due to
                     * potential races with other processes, and certainly
                     * cannot clear it if we don't commit.
                     */
                    int cm = nfsv3_commit_on_close ? 1 : 0;
                    error = nfs_flush(vp, MNT_WAIT, td, cm);
                    /* np->n_flag &= ~NLMODIFIED; */
                } else {
                    error = nfs_vinvalbuf(vp, V_SAVE, 1);
                }
                np->n_attrstamp = 0;
            }
            if (np->n_flag & NWRITEERR) {
                np->n_flag &= ~NWRITEERR;
                error = np->n_error;
            }
        }
        vop_stdclose(ap);
        lwkt_reltoken(&nmp->nm_token);

        return (error);
}

/*
 * nfs getattr call from vfs.
 *
 * nfs_getattr(struct vnode *a_vp, struct vattr *a_vap)
 */
static int
nfs_getattr(struct vop_getattr_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct nfsmount *nmp;
        int error = 0;
        thread_t td = curthread;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(vp);
        nmp = VFSTONFS(vp->v_mount);

        lwkt_gettoken(&nmp->nm_token);
        
        /*
         * Update local times for special files.
         */
        if (np->n_flag & (NACC | NUPD))
                np->n_flag |= NCHG;
        /*
         * First look in the cache.
         */
        if (nfs_getattrcache(vp, ap->a_vap) == 0)
                goto done;

        if (info.v3 && nfsaccess_cache_timeout > 0) {
                nfsstats.accesscache_misses++;
                nfs3_access_otw(vp, NFSV3ACCESS_ALL, td, nfs_vpcred(vp, ND_CHECK));
                if (nfs_getattrcache(vp, ap->a_vap) == 0)
                        goto done;
        }

        nfsstats.rpccnt[NFSPROC_GETATTR]++;
        nfsm_reqhead(&info, vp, NFSPROC_GETATTR, NFSX_FH(info.v3));
        ERROROUT(nfsm_fhtom(&info, vp));
        NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_GETATTR, td,
                                nfs_vpcred(vp, ND_CHECK), &error));
        if (error == 0) {
                ERROROUT(nfsm_loadattr(&info, vp, ap->a_vap));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
done:
        /*
         * NFS doesn't support chflags flags.  If the nfs mount was
         * made -o cache set the UF_CACHE bit for swapcache.
         */
        if ((nmp->nm_flag & NFSMNT_CACHE) && (vp->v_flag & VROOT))
                ap->a_vap->va_flags |= UF_CACHE;
nfsmout:
        lwkt_reltoken(&nmp->nm_token);
        return (error);
}

/*
 * nfs setattr call.
 *
 * nfs_setattr(struct vnode *a_vp, struct vattr *a_vap, struct ucred *a_cred)
 */
static int
nfs_setattr(struct vop_setattr_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        struct vattr *vap = ap->a_vap;
        int error = 0;
        int kflags = 0;
        off_t tsize;
        thread_t td = curthread;

#ifndef nolint
        tsize = (off_t)0;
#endif
        /*
         * Setting of flags is not supported.
         */
        if (vap->va_flags != VNOVAL)
                return (EOPNOTSUPP);

        /*
         * Disallow write attempts if the filesystem is mounted read-only.
         */
        if ((vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
            vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
            vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL) &&
            (vp->v_mount->mnt_flag & MNT_RDONLY))
                return (EROFS);

        lwkt_gettoken(&nmp->nm_token);

        /*
         * Handle size changes
         */
        if (vap->va_size != VNOVAL) {
                /*
                 * truncation requested
                 */
                switch (vp->v_type) {
                case VDIR:
                        lwkt_reltoken(&nmp->nm_token);
                        return (EISDIR);
                case VCHR:
                case VBLK:
                case VSOCK:
                case VFIFO:
                        if (vap->va_mtime.tv_sec == VNOVAL &&
                            vap->va_atime.tv_sec == VNOVAL &&
                            vap->va_mode == (mode_t)VNOVAL &&
                            vap->va_uid == (uid_t)VNOVAL &&
                            vap->va_gid == (gid_t)VNOVAL) {
                                lwkt_reltoken(&nmp->nm_token);
                                return (0);
                        }
                        vap->va_size = VNOVAL;
                        break;
                default:
                        /*
                         * Disallow write attempts if the filesystem is
                         * mounted read-only.
                         */
                        if (vp->v_mount->mnt_flag & MNT_RDONLY) {
                                lwkt_reltoken(&nmp->nm_token);
                                return (EROFS);
                        }

                        tsize = np->n_size;
again:
                        error = nfs_meta_setsize(vp, td, vap->va_size, 0);

#if 0
                        if (np->n_flag & NLMODIFIED) {
                            if (vap->va_size == 0)
                                error = nfs_vinvalbuf(vp, 0, 1);
                            else
                                error = nfs_vinvalbuf(vp, V_SAVE, 1);
                        }
#endif
                        /*
                         * note: this loop case almost always happens at 
                         * least once per truncation.
                         */
                        if (error == 0 && np->n_size != vap->va_size)
                                goto again;
                        np->n_vattr.va_size = vap->va_size;
                        kflags |= NOTE_WRITE;
                        if (tsize < vap->va_size)
                                kflags |= NOTE_EXTEND;
                        break;
                }
        }

        /*
         * If setting the mtime or if server/other-client modifications have
         * been detected, we must fully flush any pending writes.
         *
         * This will slow down cp/cpdup/rdist/rsync and other operations which
         * might call [l]utimes() to set the mtime after writing to a file,
         * but honestly there is no way to properly defer the write flush
         * and still get reasonably accurate/dependable synchronization of
         * [l]utimes().
         */
        if ((np->n_flag & NLMODIFIED) && vp->v_type == VREG) {
                if ((np->n_flag & NRMODIFIED) ||
                    (vap->va_mtime.tv_sec != VNOVAL)) {
                        error = nfs_vinvalbuf(vp, V_SAVE, 1);
                        if (error == EINTR) {
                                lwkt_reltoken(&nmp->nm_token);
                                return (error);
                        }
                }
        }

        /*
         * Get the blasted mtime to report properly.
         */
        if (vap->va_mtime.tv_sec != VNOVAL) {
                np->n_mtime = vap->va_mtime.tv_sec;
                np->n_flag &= ~NUPD;
                np->n_vattr.va_mtime = vap->va_mtime;
        }

        /*
         * Issue the setattr rpc, adjust our mtime and make sure NUPD
         * has been cleared so it does not get overridden.
         */
        error = nfs_setattrrpc(vp, vap, ap->a_cred, td);
        if (error == 0)
                kflags |= NOTE_EXTEND;

        /*
         * Sanity check if a truncation was issued.  This should only occur
         * if multiple processes are racing on the same file.
         */
        if (error == 0 && vap->va_size != VNOVAL && 
            np->n_size != vap->va_size) {
                kprintf("NFS ftruncate: server disagrees on the file size: "
                        "%jd/%jd/%jd\n",
                        (intmax_t)tsize,
                        (intmax_t)vap->va_size,
                        (intmax_t)np->n_size);
                goto again;
        }
        if (error && vap->va_size != VNOVAL) {
                np->n_size = np->n_vattr.va_size = tsize;
                nfs_meta_setsize(vp, td, np->n_size, 0);
        }
        lwkt_reltoken(&nmp->nm_token);
        nfs_knote(vp, kflags);

        return (error);
}

/*
 * Do an nfs setattr rpc.
 */
static int
nfs_setattrrpc(struct vnode *vp, struct vattr *vap,
               struct ucred *cred, struct thread *td)
{
        struct nfsv2_sattr *sp;
        struct nfsnode *np = VTONFS(vp);
        u_int32_t *tl;
        int error = 0, wccflag = NFSV3_WCCRATTR;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(vp);

        nfsstats.rpccnt[NFSPROC_SETATTR]++;
        nfsm_reqhead(&info, vp, NFSPROC_SETATTR,
                     NFSX_FH(info.v3) + NFSX_SATTR(info.v3));
        ERROROUT(nfsm_fhtom(&info, vp));
        if (info.v3) {
                nfsm_v3attrbuild(&info, vap, TRUE);
                tl = nfsm_build(&info, NFSX_UNSIGNED);
                *tl = nfs_false;
        } else {
                sp = nfsm_build(&info, NFSX_V2SATTR);
                if (vap->va_mode == (mode_t)VNOVAL)
                        sp->sa_mode = nfs_xdrneg1;
                else
                        sp->sa_mode = vtonfsv2_mode(vp->v_type, vap->va_mode);
                if (vap->va_uid == (uid_t)VNOVAL)
                        sp->sa_uid = nfs_xdrneg1;
                else
                        sp->sa_uid = txdr_unsigned(vap->va_uid);
                if (vap->va_gid == (gid_t)VNOVAL)
                        sp->sa_gid = nfs_xdrneg1;
                else
                        sp->sa_gid = txdr_unsigned(vap->va_gid);
                sp->sa_size = txdr_unsigned(vap->va_size);
                txdr_nfsv2time(&vap->va_atime, &sp->sa_atime);
                txdr_nfsv2time(&vap->va_mtime, &sp->sa_mtime);
        }
        NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_SETATTR, td, cred, &error));
        if (info.v3) {
                np->n_modestamp = 0;
                ERROROUT(nfsm_wcc_data(&info, vp, &wccflag));
        } else {
                ERROROUT(nfsm_loadattr(&info, vp, NULL));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        return (error);
}

static
void
nfs_cache_setvp(struct nchandle *nch, struct vnode *vp, int nctimeout)
{
        if (nctimeout == 0)
                nctimeout = 1;
        else
                nctimeout *= hz;
        cache_setvp(nch, vp);
        cache_settimeout(nch, nctimeout);
}

/*
 * NEW API CALL - replaces nfs_lookup().  However, we cannot remove 
 * nfs_lookup() until all remaining new api calls are implemented.
 *
 * Resolve a namecache entry.  This function is passed a locked ncp and
 * must call nfs_cache_setvp() on it as appropriate to resolve the entry.
 */
static int
nfs_nresolve(struct vop_nresolve_args *ap)
{
        struct thread *td = curthread;
        struct namecache *ncp;
        struct nfsmount *nmp;
        struct nfsnode *np;
        struct vnode *dvp;
        struct vnode *nvp;
        nfsfh_t *fhp;
        int attrflag;
        int fhsize;
        int error;
        int tmp_error;
        int len;
        struct nfsm_info info;

        dvp = ap->a_dvp;
        nmp = VFSTONFS(dvp->v_mount);

        lwkt_gettoken(&nmp->nm_token);

        if ((error = vget(dvp, LK_SHARED)) != 0) {
                lwkt_reltoken(&nmp->nm_token);
                return (error);
        }

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);

        nvp = NULL;
        nfsstats.lookupcache_misses++;
        nfsstats.rpccnt[NFSPROC_LOOKUP]++;
        ncp = ap->a_nch->ncp;
        len = ncp->nc_nlen;
        nfsm_reqhead(&info, dvp, NFSPROC_LOOKUP,
                     NFSX_FH(info.v3) + NFSX_UNSIGNED + nfsm_rndup(len));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, ncp->nc_name, len, NFS_MAXNAMLEN));
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_LOOKUP, td,
                                ap->a_cred, &error));
        if (error) {
                /*
                 * Cache negatve lookups to reduce NFS traffic, but use
                 * a fast timeout.  Otherwise use a timeout of 1 tick.
                 * XXX we should add a namecache flag for no-caching
                 * to uncache the negative hit as soon as possible, but
                 * we cannot simply destroy the entry because it is used
                 * as a placeholder by the caller.
                 *
                 * The refactored nfs code will overwrite a non-zero error
                 * with 0 when we use ERROROUT(), so don't here.
                 */
                if (error == ENOENT)
                        nfs_cache_setvp(ap->a_nch, NULL, nfsneg_cache_timeout);
                tmp_error = nfsm_postop_attr(&info, dvp, &attrflag,
                                             NFS_LATTR_NOSHRINK);
                if (tmp_error) {
                        error = tmp_error;
                        goto nfsmout;
                }
                m_freem(info.mrep);
                info.mrep = NULL;
                goto nfsmout;
        }

        /*
         * Success, get the file handle, do various checks, and load 
         * post-operation data from the reply packet.  Theoretically
         * we should never be looking up "." so, theoretically, we
         * should never get the same file handle as our directory.  But
         * we check anyway. XXX
         *
         * Note that no timeout is set for the positive cache hit.  We
         * assume, theoretically, that ESTALE returns will be dealt with
         * properly to handle NFS races and in anycase we cannot depend
         * on a timeout to deal with NFS open/create/excl issues so instead
         * of a bad hack here the rest of the NFS client code needs to do
         * the right thing.
         */
        NEGATIVEOUT(fhsize = nfsm_getfh(&info, &fhp));

        np = VTONFS(dvp);
        if (NFS_CMPFH(np, fhp, fhsize)) {
                vref(dvp);
                nvp = dvp;
        } else {
                error = nfs_nget(dvp->v_mount, fhp, fhsize, &np, NULL);
                if (error) {
                        m_freem(info.mrep);
                        info.mrep = NULL;
                        vput(dvp);
                        lwkt_reltoken(&nmp->nm_token);
                        return (error);
                }
                nvp = NFSTOV(np);
        }
        if (info.v3) {
                ERROROUT(nfsm_postop_attr(&info, nvp, &attrflag,
                                          NFS_LATTR_NOSHRINK));
                ERROROUT(nfsm_postop_attr(&info, dvp, &attrflag,
                                          NFS_LATTR_NOSHRINK));
        } else {
                ERROROUT(nfsm_loadattr(&info, nvp, NULL));
        }
        nfs_cache_setvp(ap->a_nch, nvp, nfspos_cache_timeout);
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        lwkt_reltoken(&nmp->nm_token);
        vput(dvp);
        if (nvp) {
                if (nvp == dvp)
                        vrele(nvp);
                else
                        vput(nvp);
        }
        return (error);
}

/*
 * 'cached' nfs directory lookup
 *
 * NOTE: cannot be removed until NFS implements all the new n*() API calls.
 *
 * nfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
 *            struct componentname *a_cnp)
 */
static int
nfs_lookup(struct vop_old_lookup_args *ap)
{
        struct componentname *cnp = ap->a_cnp;
        struct vnode *dvp = ap->a_dvp;
        struct vnode **vpp = ap->a_vpp;
        int flags = cnp->cn_flags;
        struct vnode *newvp;
        struct vnode *notvp;
        struct nfsmount *nmp;
        long len;
        nfsfh_t *fhp;
        struct nfsnode *np;
        int lockparent, wantparent, attrflag, fhsize;
        int error;
        int tmp_error;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);
        error = 0;

        notvp = (cnp->cn_flags & CNP_NOTVP) ? cnp->cn_notvp : NULL;

        /*
         * Read-only mount check and directory check.
         */
        *vpp = NULLVP;
        if ((dvp->v_mount->mnt_flag & MNT_RDONLY) &&
            (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME))
                return (EROFS);

        if (dvp->v_type != VDIR)
                return (ENOTDIR);

        /*
         * Look it up in the cache.  Note that ENOENT is only returned if we
         * previously entered a negative hit (see later on).  The additional
         * nfsneg_cache_timeout check causes previously cached results to
         * be instantly ignored if the negative caching is turned off.
         */
        lockparent = flags & CNP_LOCKPARENT;
        wantparent = flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
        nmp = VFSTONFS(dvp->v_mount);
        np = VTONFS(dvp);

        lwkt_gettoken(&nmp->nm_token);

        /*
         * Go to the wire.
         */
        error = 0;
        newvp = NULLVP;
        nfsstats.lookupcache_misses++;
        nfsstats.rpccnt[NFSPROC_LOOKUP]++;
        len = cnp->cn_namelen;
        nfsm_reqhead(&info, dvp, NFSPROC_LOOKUP,
                     NFSX_FH(info.v3) + NFSX_UNSIGNED + nfsm_rndup(len));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, cnp->cn_nameptr, len, NFS_MAXNAMLEN));
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_LOOKUP, cnp->cn_td,
                                cnp->cn_cred, &error));
        if (error) {
                tmp_error = nfsm_postop_attr(&info, dvp, &attrflag,
                                             NFS_LATTR_NOSHRINK);
                if (tmp_error) {
                        error = tmp_error;
                        goto nfsmout;
                }

                m_freem(info.mrep);
                info.mrep = NULL;
                goto nfsmout;
        }
        NEGATIVEOUT(fhsize = nfsm_getfh(&info, &fhp));

        /*
         * Handle RENAME case...
         */
        if (cnp->cn_nameiop == NAMEI_RENAME && wantparent) {
                if (NFS_CMPFH(np, fhp, fhsize)) {
                        m_freem(info.mrep);
                        info.mrep = NULL;
                        lwkt_reltoken(&nmp->nm_token);
                        return (EISDIR);
                }
                error = nfs_nget(dvp->v_mount, fhp, fhsize, &np, notvp);
                if (error) {
                        m_freem(info.mrep);
                        info.mrep = NULL;
                        lwkt_reltoken(&nmp->nm_token);
                        return (error);
                }
                newvp = NFSTOV(np);
                if (info.v3) {
                        ERROROUT(nfsm_postop_attr(&info, newvp, &attrflag,
                                                  NFS_LATTR_NOSHRINK));
                        ERROROUT(nfsm_postop_attr(&info, dvp, &attrflag,
                                                  NFS_LATTR_NOSHRINK));
                } else {
                        ERROROUT(nfsm_loadattr(&info, newvp, NULL));
                }
                *vpp = newvp;
                m_freem(info.mrep);
                info.mrep = NULL;
                if (!lockparent) {
                        vn_unlock(dvp);
                        cnp->cn_flags |= CNP_PDIRUNLOCK;
                }
                lwkt_reltoken(&nmp->nm_token);
                return (0);
        }

        if (flags & CNP_ISDOTDOT) {
                vn_unlock(dvp);
                cnp->cn_flags |= CNP_PDIRUNLOCK;
                error = nfs_nget(dvp->v_mount, fhp, fhsize, &np, notvp);
                if (error) {
                        vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
                        cnp->cn_flags &= ~CNP_PDIRUNLOCK;
                        lwkt_reltoken(&nmp->nm_token);
                        return (error); /* NOTE: return error from nget */
                }
                newvp = NFSTOV(np);
                if (lockparent) {
                        error = vn_lock(dvp, LK_EXCLUSIVE | LK_FAILRECLAIM);
                        if (error) {
                                vput(newvp);
                                lwkt_reltoken(&nmp->nm_token);
                                return (error);
                        }
                        cnp->cn_flags |= CNP_PDIRUNLOCK;
                }
        } else if (NFS_CMPFH(np, fhp, fhsize)) {
                vref(dvp);
                newvp = dvp;
        } else {
                error = nfs_nget(dvp->v_mount, fhp, fhsize, &np, notvp);
                if (error) {
                        m_freem(info.mrep);
                        info.mrep = NULL;
                        lwkt_reltoken(&nmp->nm_token);
                        return (error);
                }
                if (!lockparent) {
                        vn_unlock(dvp);
                        cnp->cn_flags |= CNP_PDIRUNLOCK;
                }
                newvp = NFSTOV(np);
        }
        if (info.v3) {
                ERROROUT(nfsm_postop_attr(&info, newvp, &attrflag,
                                          NFS_LATTR_NOSHRINK));
                ERROROUT(nfsm_postop_attr(&info, dvp, &attrflag,
                                          NFS_LATTR_NOSHRINK));
        } else {
                ERROROUT(nfsm_loadattr(&info, newvp, NULL));
        }
#if 0
        /* XXX MOVE TO nfs_nremove() */
        if ((cnp->cn_flags & CNP_MAKEENTRY) &&
            cnp->cn_nameiop != NAMEI_DELETE) {
                np->n_ctime = np->n_vattr.va_ctime.tv_sec; /* XXX */
        }
#endif
        *vpp = newvp;
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        if (error) {
                if (newvp != NULLVP) {
                        vrele(newvp);
                        *vpp = NULLVP;
                }
                if ((cnp->cn_nameiop == NAMEI_CREATE || 
                     cnp->cn_nameiop == NAMEI_RENAME) &&
                    error == ENOENT) {
                        if (!lockparent) {
                                vn_unlock(dvp);
                                cnp->cn_flags |= CNP_PDIRUNLOCK;
                        }
                        if (dvp->v_mount->mnt_flag & MNT_RDONLY)
                                error = EROFS;
                        else
                                error = EJUSTRETURN;
                }
        }
        lwkt_reltoken(&nmp->nm_token);
        return (error);
}

/*
 * nfs read call.
 * Just call nfs_bioread() to do the work.
 *
 * nfs_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
 *          struct ucred *a_cred)
 */
static int
nfs_read(struct vop_read_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        int error;

        lwkt_gettoken(&nmp->nm_token);
        error = nfs_bioread(vp, ap->a_uio, ap->a_ioflag);
        lwkt_reltoken(&nmp->nm_token);

        return error;
}

/*
 * nfs readlink call
 *
 * nfs_readlink(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
 */
static int
nfs_readlink(struct vop_readlink_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        int error;

        if (vp->v_type != VLNK)
                return (EINVAL);

        lwkt_gettoken(&nmp->nm_token);
        error = nfs_bioread(vp, ap->a_uio, 0);
        lwkt_reltoken(&nmp->nm_token);

        return error;
}

/*
 * Do a readlink rpc.
 * Called by nfs_doio() from below the buffer cache.
 */
int
nfs_readlinkrpc_uio(struct vnode *vp, struct uio *uiop)
{
        int error = 0, len, attrflag;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(vp);

        nfsstats.rpccnt[NFSPROC_READLINK]++;
        nfsm_reqhead(&info, vp, NFSPROC_READLINK, NFSX_FH(info.v3));
        ERROROUT(nfsm_fhtom(&info, vp));
        NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_READLINK, uiop->uio_td,
                                nfs_vpcred(vp, ND_CHECK), &error));
        if (info.v3) {
                ERROROUT(nfsm_postop_attr(&info, vp, &attrflag,
                                          NFS_LATTR_NOSHRINK));
        }
        if (!error) {
                NEGATIVEOUT(len = nfsm_strsiz(&info, NFS_MAXPATHLEN));
                if (len == NFS_MAXPATHLEN) {
                        struct nfsnode *np = VTONFS(vp);
                        if (np->n_size && np->n_size < NFS_MAXPATHLEN)
                                len = np->n_size;
                }
                ERROROUT(nfsm_mtouio(&info, uiop, len));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        return (error);
}

/*
 * nfs synchronous read rpc using UIO
 */
int
nfs_readrpc_uio(struct vnode *vp, struct uio *uiop)
{
        u_int32_t *tl;
        struct nfsmount *nmp;
        int error = 0, len, retlen, tsiz, eof, attrflag;
        struct nfsm_info info;
        off_t tmp_off;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(vp);

#ifndef nolint
        eof = 0;
#endif
        nmp = VFSTONFS(vp->v_mount);

        tsiz = uiop->uio_resid;
        tmp_off = uiop->uio_offset + tsiz;
        if (tmp_off > nmp->nm_maxfilesize || tmp_off < uiop->uio_offset)
                return (EFBIG);
        tmp_off = uiop->uio_offset;
        while (tsiz > 0) {
                nfsstats.rpccnt[NFSPROC_READ]++;
                len = (tsiz > nmp->nm_rsize) ? nmp->nm_rsize : tsiz;
                nfsm_reqhead(&info, vp, NFSPROC_READ,
                             NFSX_FH(info.v3) + NFSX_UNSIGNED * 3);
                ERROROUT(nfsm_fhtom(&info, vp));
                tl = nfsm_build(&info, NFSX_UNSIGNED * 3);
                if (info.v3) {
                        txdr_hyper(uiop->uio_offset, tl);
                        *(tl + 2) = txdr_unsigned(len);
                } else {
                        *tl++ = txdr_unsigned(uiop->uio_offset);
                        *tl++ = txdr_unsigned(len);
                        *tl = 0;
                }
                NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_READ, uiop->uio_td,
                                        nfs_vpcred(vp, ND_READ), &error));
                if (info.v3) {
                        ERROROUT(nfsm_postop_attr(&info, vp, &attrflag,
                                                 NFS_LATTR_NOSHRINK));
                        NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
                        eof = fxdr_unsigned(int, *(tl + 1));
                } else {
                        ERROROUT(nfsm_loadattr(&info, vp, NULL));
                }
                NEGATIVEOUT(retlen = nfsm_strsiz(&info, len));
                ERROROUT(nfsm_mtouio(&info, uiop, retlen));
                m_freem(info.mrep);
                info.mrep = NULL;

                /*
                 * Handle short-read from server (NFSv3).  If EOF is not
                 * flagged (and no error occurred), but retlen is less
                 * then the request size, we must zero-fill the remainder.
                 */
                if (retlen < len && info.v3 && eof == 0) {
                        ERROROUT(uiomovez(len - retlen, uiop));
                        retlen = len;
                }
                tsiz -= retlen;

                /*
                 * Terminate loop on EOF or zero-length read.
                 *
                 * For NFSv2 a short-read indicates EOF, not zero-fill,
                 * and also terminates the loop.
                 */
                if (info.v3) {
                        if (eof || retlen == 0)
                                tsiz = 0;
                } else if (retlen < len) {
                        tsiz = 0;
                }
        }
nfsmout:
        return (error);
}

/*
 * nfs write call
 */
int
nfs_writerpc_uio(struct vnode *vp, struct uio *uiop,
                 int *iomode, int *must_commit)
{
        u_int32_t *tl;
        int32_t backup;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        int error = 0, len, tsiz, wccflag = NFSV3_WCCRATTR, rlen, commit;
        int  committed = NFSV3WRITE_FILESYNC;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(vp);

#ifndef DIAGNOSTIC
        if (uiop->uio_iovcnt != 1)
                panic("nfs: writerpc iovcnt > 1");
#endif
        *must_commit = 0;
        tsiz = uiop->uio_resid;
        if (uiop->uio_offset + tsiz > nmp->nm_maxfilesize)
                return (EFBIG);
        while (tsiz > 0) {
                nfsstats.rpccnt[NFSPROC_WRITE]++;
                len = (tsiz > nmp->nm_wsize) ? nmp->nm_wsize : tsiz;
                nfsm_reqhead(&info, vp, NFSPROC_WRITE,
                             NFSX_FH(info.v3) + 5 * NFSX_UNSIGNED +
                             nfsm_rndup(len));
                ERROROUT(nfsm_fhtom(&info, vp));
                if (info.v3) {
                        tl = nfsm_build(&info, 5 * NFSX_UNSIGNED);
                        txdr_hyper(uiop->uio_offset, tl);
                        tl += 2;
                        *tl++ = txdr_unsigned(len);
                        *tl++ = txdr_unsigned(*iomode);
                        *tl = txdr_unsigned(len);
                } else {
                        u_int32_t x;

                        tl = nfsm_build(&info, 4 * NFSX_UNSIGNED);
                        /* Set both "begin" and "current" to non-garbage. */
                        x = txdr_unsigned((u_int32_t)uiop->uio_offset);
                        *tl++ = x;      /* "begin offset" */
                        *tl++ = x;      /* "current offset" */
                        x = txdr_unsigned(len);
                        *tl++ = x;      /* total to this offset */
                        *tl = x;        /* size of this write */
                }
                ERROROUT(nfsm_uiotom(&info, uiop, len));
                NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_WRITE, uiop->uio_td,
                                        nfs_vpcred(vp, ND_WRITE), &error));
                if (info.v3) {
                        /*
                         * The write RPC returns a before and after mtime.  The
                         * nfsm_wcc_data() macro checks the before n_mtime
                         * against the before time and stores the after time
                         * in the nfsnode's cached vattr and n_mtime field.
                         * The NRMODIFIED bit will be set if the before
                         * time did not match the original mtime.
                         */
                        wccflag = NFSV3_WCCCHK;
                        ERROROUT(nfsm_wcc_data(&info, vp, &wccflag));
                        if (error == 0) {
                                NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED + NFSX_V3WRITEVERF));
                                rlen = fxdr_unsigned(int, *tl++);
                                if (rlen == 0) {
                                        error = NFSERR_IO;
                                        m_freem(info.mrep);
                                        info.mrep = NULL;
                                        break;
                                } else if (rlen < len) {
                                        backup = len - rlen;
                                        uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base - backup;
                                        uiop->uio_iov->iov_len += backup;
                                        uiop->uio_offset -= backup;
                                        uiop->uio_resid += backup;
                                        len = rlen;
                                }
                                commit = fxdr_unsigned(int, *tl++);

                                /*
                                 * Return the lowest committment level
                                 * obtained by any of the RPCs.
                                 */
                                if (committed == NFSV3WRITE_FILESYNC)
                                        committed = commit;
                                else if (committed == NFSV3WRITE_DATASYNC &&
                                        commit == NFSV3WRITE_UNSTABLE)
                                        committed = commit;
                                if ((nmp->nm_state & NFSSTA_HASWRITEVERF) == 0){
                                    bcopy((caddr_t)tl, (caddr_t)nmp->nm_verf,
                                        NFSX_V3WRITEVERF);
                                    nmp->nm_state |= NFSSTA_HASWRITEVERF;
                                } else if (bcmp((caddr_t)tl,
                                    (caddr_t)nmp->nm_verf, NFSX_V3WRITEVERF)) {
                                    *must_commit = 1;
                                    bcopy((caddr_t)tl, (caddr_t)nmp->nm_verf,
                                        NFSX_V3WRITEVERF);
                                }
                        }
                } else {
                        ERROROUT(nfsm_loadattr(&info, vp, NULL));
                }
                m_freem(info.mrep);
                info.mrep = NULL;
                if (error)
                        break;
                tsiz -= len;
        }
nfsmout:
        if (vp->v_mount->mnt_flag & MNT_ASYNC)
                committed = NFSV3WRITE_FILESYNC;
        *iomode = committed;
        if (error)
                uiop->uio_resid = tsiz;
        return (error);
}

/*
 * nfs mknod rpc
 * For NFS v2 this is a kludge. Use a create rpc but with the IFMT bits of the
 * mode set to specify the file type and the size field for rdev.
 */
static int
nfs_mknodrpc(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
             struct vattr *vap)
{
        struct nfsv2_sattr *sp;
        u_int32_t *tl;
        struct vnode *newvp = NULL;
        struct nfsnode *np = NULL;
        struct vattr vattr;
        int error = 0, wccflag = NFSV3_WCCRATTR, gotvp = 0;
        int rmajor, rminor;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);

        if (vap->va_type == VCHR || vap->va_type == VBLK) {
                rmajor = txdr_unsigned(vap->va_rmajor);
                rminor = txdr_unsigned(vap->va_rminor);
        } else if (vap->va_type == VFIFO || vap->va_type == VSOCK) {
                rmajor = nfs_xdrneg1;
                rminor = nfs_xdrneg1;
        } else {
                return (EOPNOTSUPP);
        }
        if ((error = VOP_GETATTR(dvp, &vattr)) != 0) {
                return (error);
        }
        nfsstats.rpccnt[NFSPROC_MKNOD]++;
        nfsm_reqhead(&info, dvp, NFSPROC_MKNOD,
                     NFSX_FH(info.v3) + 4 * NFSX_UNSIGNED +
                     nfsm_rndup(cnp->cn_namelen) + NFSX_SATTR(info.v3));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, cnp->cn_nameptr, cnp->cn_namelen,
                             NFS_MAXNAMLEN));
        if (info.v3) {
                tl = nfsm_build(&info, NFSX_UNSIGNED);
                *tl++ = vtonfsv3_type(vap->va_type);
                nfsm_v3attrbuild(&info, vap, FALSE);
                if (vap->va_type == VCHR || vap->va_type == VBLK) {
                        tl = nfsm_build(&info, 2 * NFSX_UNSIGNED);
                        *tl++ = txdr_unsigned(vap->va_rmajor);
                        *tl = txdr_unsigned(vap->va_rminor);
                }
        } else {
                sp = nfsm_build(&info, NFSX_V2SATTR);
                sp->sa_mode = vtonfsv2_mode(vap->va_type, vap->va_mode);
                sp->sa_uid = nfs_xdrneg1;
                sp->sa_gid = nfs_xdrneg1;
                sp->sa_size = makeudev(rmajor, rminor);
                txdr_nfsv2time(&vap->va_atime, &sp->sa_atime);
                txdr_nfsv2time(&vap->va_mtime, &sp->sa_mtime);
        }
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_MKNOD, cnp->cn_td,
                                cnp->cn_cred, &error));
        if (!error) {
                ERROROUT(nfsm_mtofh(&info, dvp, &newvp, &gotvp));
                if (!gotvp) {
                        if (newvp) {
                                vput(newvp);
                                newvp = NULL;
                        }
                        error = nfs_lookitup(dvp, cnp->cn_nameptr,
                            cnp->cn_namelen, cnp->cn_cred, cnp->cn_td, &np);
                        if (!error)
                                newvp = NFSTOV(np);
                }
        }
        if (info.v3) {
                ERROROUT(nfsm_wcc_data(&info, dvp, &wccflag));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        if (error) {
                if (newvp)
                        vput(newvp);
        } else {
                *vpp = newvp;
        }
        VTONFS(dvp)->n_flag |= NLMODIFIED;
        if (!wccflag)
                VTONFS(dvp)->n_attrstamp = 0;
        return (error);
}

/*
 * nfs mknod vop
 * just call nfs_mknodrpc() to do the work.
 *
 * nfs_mknod(struct vnode *a_dvp, struct vnode **a_vpp,
 *           struct componentname *a_cnp, struct vattr *a_vap)
 */
/* ARGSUSED */
static int
nfs_mknod(struct vop_old_mknod_args *ap)
{
        struct nfsmount *nmp = VFSTONFS(ap->a_dvp->v_mount);
        int error;

        lwkt_gettoken(&nmp->nm_token);
        error = nfs_mknodrpc(ap->a_dvp, ap->a_vpp, ap->a_cnp, ap->a_vap);
        lwkt_reltoken(&nmp->nm_token);
        if (error == 0)
                nfs_knote(ap->a_dvp, NOTE_WRITE);

        return error;
}

static u_long create_verf;
/*
 * nfs file create call
 *
 * nfs_create(struct vnode *a_dvp, struct vnode **a_vpp,
 *            struct componentname *a_cnp, struct vattr *a_vap)
 */
static int
nfs_create(struct vop_old_create_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct vattr *vap = ap->a_vap;
        struct nfsmount *nmp = VFSTONFS(dvp->v_mount);
        struct componentname *cnp = ap->a_cnp;
        struct nfsv2_sattr *sp;
        u_int32_t *tl;
        struct nfsnode *np = NULL;
        struct vnode *newvp = NULL;
        int error = 0, wccflag = NFSV3_WCCRATTR, gotvp = 0, fmode = 0;
        struct vattr vattr;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);
        lwkt_gettoken(&nmp->nm_token);

        /*
         * Oops, not for me..
         */
        if (vap->va_type == VSOCK) {
                error = nfs_mknodrpc(dvp, ap->a_vpp, cnp, vap);
                lwkt_reltoken(&nmp->nm_token);
                return error;
        }

        if ((error = VOP_GETATTR(dvp, &vattr)) != 0) {
                lwkt_reltoken(&nmp->nm_token);
                return (error);
        }
        if (vap->va_vaflags & VA_EXCLUSIVE)
                fmode |= O_EXCL;
again:
        nfsstats.rpccnt[NFSPROC_CREATE]++;
        nfsm_reqhead(&info, dvp, NFSPROC_CREATE,
                     NFSX_FH(info.v3) + 2 * NFSX_UNSIGNED +
                     nfsm_rndup(cnp->cn_namelen) + NFSX_SATTR(info.v3));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, cnp->cn_nameptr, cnp->cn_namelen,
                             NFS_MAXNAMLEN));
        if (info.v3) {
                tl = nfsm_build(&info, NFSX_UNSIGNED);
                if (fmode & O_EXCL) {
                        *tl = txdr_unsigned(NFSV3CREATE_EXCLUSIVE);
                        tl = nfsm_build(&info, NFSX_V3CREATEVERF);
#ifdef INET
                        if (!TAILQ_EMPTY(&in_ifaddrheads[mycpuid]))
                                *tl++ = IA_SIN(TAILQ_FIRST(&in_ifaddrheads[mycpuid])->ia)->sin_addr.s_addr;
                        else
#endif
                                *tl++ = create_verf;
                        *tl = ++create_verf;
                } else {
                        *tl = txdr_unsigned(NFSV3CREATE_UNCHECKED);
                        nfsm_v3attrbuild(&info, vap, FALSE);
                }
        } else {
                sp = nfsm_build(&info, NFSX_V2SATTR);
                sp->sa_mode = vtonfsv2_mode(vap->va_type, vap->va_mode);
                sp->sa_uid = nfs_xdrneg1;
                sp->sa_gid = nfs_xdrneg1;
                sp->sa_size = 0;
                txdr_nfsv2time(&vap->va_atime, &sp->sa_atime);
                txdr_nfsv2time(&vap->va_mtime, &sp->sa_mtime);
        }
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_CREATE, cnp->cn_td,
                                cnp->cn_cred, &error));
        if (error == 0) {
                ERROROUT(nfsm_mtofh(&info, dvp, &newvp, &gotvp));
                if (!gotvp) {
                        if (newvp) {
                                vput(newvp);
                                newvp = NULL;
                        }
                        error = nfs_lookitup(dvp, cnp->cn_nameptr,
                            cnp->cn_namelen, cnp->cn_cred, cnp->cn_td, &np);
                        if (!error)
                                newvp = NFSTOV(np);
                }
        }
        if (info.v3) {
                if (error == 0)
                        error = nfsm_wcc_data(&info, dvp, &wccflag);
                else
                        (void)nfsm_wcc_data(&info, dvp, &wccflag);
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        if (error) {
                if (info.v3 && (fmode & O_EXCL) && error == NFSERR_NOTSUPP) {
                        KKASSERT(newvp == NULL);
                        fmode &= ~O_EXCL;
                        goto again;
                }
        } else if (info.v3 && (fmode & O_EXCL)) {
                /*
                 * We are normally called with only a partially initialized
                 * VAP.  Since the NFSv3 spec says that server may use the
                 * file attributes to store the verifier, the spec requires
                 * us to do a SETATTR RPC. FreeBSD servers store the verifier
                 * in atime, but we can't really assume that all servers will
                 * so we ensure that our SETATTR sets both atime and mtime.
                 */
                if (vap->va_mtime.tv_sec == VNOVAL)
                        vfs_timestamp(&vap->va_mtime);
                if (vap->va_atime.tv_sec == VNOVAL)
                        vap->va_atime = vap->va_mtime;
                error = nfs_setattrrpc(newvp, vap, cnp->cn_cred, cnp->cn_td);
        }
        if (error == 0) {
                /*
                 * The new np may have enough info for access
                 * checks, make sure rucred and wucred are
                 * initialized for read and write rpc's.
                 */
                np = VTONFS(newvp);
                if (np->n_rucred == NULL)
                        np->n_rucred = nfs_crhold(cnp->cn_cred);
                if (np->n_wucred == NULL)
                        np->n_wucred = nfs_crhold(cnp->cn_cred);
                *ap->a_vpp = newvp;
                nfs_knote(dvp, NOTE_WRITE);
        } else if (newvp) {
                vput(newvp);
        }
        VTONFS(dvp)->n_flag |= NLMODIFIED;
        if (!wccflag)
                VTONFS(dvp)->n_attrstamp = 0;
        lwkt_reltoken(&nmp->nm_token);
        return (error);
}

/*
 * nfs file remove call
 * To try and make nfs semantics closer to ufs semantics, a file that has
 * other processes using the vnode is renamed instead of removed and then
 * removed later on the last close.
 * - If v_refcnt > 1
 *        If a rename is not already in the works
 *           call nfs_sillyrename() to set it up
 *     else
 *        do the remove rpc
 *
 * nfs_remove(struct vnode *a_dvp, struct vnode *a_vp,
 *            struct componentname *a_cnp)
 */
static int
nfs_remove(struct vop_old_remove_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct nfsmount *nmp = VFSTONFS(dvp->v_mount);
        struct componentname *cnp = ap->a_cnp;
        struct nfsnode *np = VTONFS(vp);
        int error = 0;
        struct vattr vattr;

        lwkt_gettoken(&nmp->nm_token);
#ifndef DIAGNOSTIC
        if (VREFCNT(vp) < 1)
                panic("nfs_remove: bad v_refcnt");
#endif
        if (vp->v_type == VDIR) {
                error = EPERM;
        } else if (VREFCNT(vp) == 1 || (np->n_sillyrename &&
                   VOP_GETATTR(vp, &vattr) == 0 && vattr.va_nlink > 1)) {
                /*
                 * Force finalization so the VOP_INACTIVE() call is not delayed.
                 * This prevents cred structures from building up in nfsnodes
                 * for deleted files.
                 */
                atomic_set_int(&vp->v_refcnt, VREF_FINALIZE);
                np->n_flag |= NREMOVED;

                /*
                 * Throw away biocache buffers, mainly to avoid
                 * unnecessary delayed writes later.
                 */
                error = nfs_vinvalbuf(vp, 0, 1);
                /* Do the rpc */
                if (error != EINTR) {
                        error = nfs_removerpc(dvp, cnp->cn_nameptr,
                                              cnp->cn_namelen,
                                              cnp->cn_cred, cnp->cn_td);
                }

                /*
                 * Kludge City: If the first reply to the remove rpc is lost..
                 *   the reply to the retransmitted request will be ENOENT
                 *   since the file was in fact removed
                 *   Therefore, we cheat and return success.
                 */
                if (error == ENOENT)
                        error = 0;
        } else if (!np->n_sillyrename) {
                error = nfs_sillyrename(dvp, vp, cnp);
        }
        np->n_attrstamp = 0;
        lwkt_reltoken(&nmp->nm_token);
        if (error == 0) {
                nfs_knote(vp, NOTE_DELETE);
                nfs_knote(dvp, NOTE_WRITE);
        }

        return (error);
}

/*
 * nfs file remove rpc called from nfs_inactive
 *
 * NOTE: s_dvp can be VBAD during a forced unmount.
 */
int
nfs_removeit(struct sillyrename *sp)
{
        if (sp->s_dvp->v_type == VBAD)
                return(0);
        return (nfs_removerpc(sp->s_dvp, sp->s_name, sp->s_namlen,
                sp->s_cred, NULL));
}

/*
 * Nfs remove rpc, called from nfs_remove() and nfs_removeit().
 */
static int
nfs_removerpc(struct vnode *dvp, const char *name, int namelen,
              struct ucred *cred, struct thread *td)
{
        int error = 0, wccflag = NFSV3_WCCRATTR;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);

        nfsstats.rpccnt[NFSPROC_REMOVE]++;
        nfsm_reqhead(&info, dvp, NFSPROC_REMOVE,
                     NFSX_FH(info.v3) + NFSX_UNSIGNED + nfsm_rndup(namelen));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, name, namelen, NFS_MAXNAMLEN));
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_REMOVE, td, cred, &error));
        if (info.v3) {
                ERROROUT(nfsm_wcc_data(&info, dvp, &wccflag));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        VTONFS(dvp)->n_flag |= NLMODIFIED;
        if (!wccflag)
                VTONFS(dvp)->n_attrstamp = 0;
        return (error);
}

/*
 * nfs file rename call
 *
 * nfs_rename(struct vnode *a_fdvp, struct vnode *a_fvp,
 *            struct componentname *a_fcnp, struct vnode *a_tdvp,
 *            struct vnode *a_tvp, struct componentname *a_tcnp)
 */
static int
nfs_rename(struct vop_old_rename_args *ap)
{
        struct vnode *fvp = ap->a_fvp;
        struct vnode *tvp = ap->a_tvp;
        struct vnode *fdvp = ap->a_fdvp;
        struct vnode *tdvp = ap->a_tdvp;
        struct componentname *tcnp = ap->a_tcnp;
        struct componentname *fcnp = ap->a_fcnp;
        struct nfsmount *nmp = VFSTONFS(fdvp->v_mount);
        int error;

        lwkt_gettoken(&nmp->nm_token);

        /*
         * Force finalization so the VOP_INACTIVE() call is not delayed.
         * This prevents cred structures from building up in nfsnodes
         * for deleted files.
         */
        if (tvp) {
                atomic_set_int(&tvp->v_refcnt, VREF_FINALIZE);
                if (VTONFS(tvp))
                        VTONFS(tvp)->n_flag |= NREMOVED;
        }

        /* Check for cross-device rename */
        if ((fvp->v_mount != tdvp->v_mount) ||
            (tvp && (fvp->v_mount != tvp->v_mount))) {
                error = EXDEV;
                goto out;
        }

        /*
         * We shouldn't have to flush fvp on rename for most server-side
         * filesystems as the file handle should not change.  Unfortunately
         * the inode for some filesystems (msdosfs) might be tied to the
         * file name or directory position so to be completely safe
         * vfs.nfs.flush_on_rename is set by default.  Clear to improve
         * performance.
         *
         * We must flush tvp on rename because it might become stale on the
         * server after the rename.
         */
        if (nfs_flush_on_rename)
            VOP_FSYNC(fvp, MNT_WAIT, 0);
        if (tvp)
            VOP_FSYNC(tvp, MNT_WAIT, 0);

        /*
         * If the tvp exists and is in use, sillyrename it before doing the
         * rename of the new file over it.
         *
         * XXX Can't sillyrename a directory.
         *
         * We do not attempt to do any namecache purges in this old API
         * routine.  The new API compat functions have access to the actual
         * namecache structures and will do it for us.
         */
        if (tvp && VREFCNT(tvp) > 1 && !VTONFS(tvp)->n_sillyrename &&
                tvp->v_type != VDIR && !nfs_sillyrename(tdvp, tvp, tcnp)) {
                nfs_knote(tvp, NOTE_DELETE);
                vput(tvp);
                tvp = NULL;
        } else if (tvp) {
                nfs_knote(tvp, NOTE_DELETE);
        }

        error = nfs_renamerpc(fdvp, fcnp->cn_nameptr, fcnp->cn_namelen,
                tdvp, tcnp->cn_nameptr, tcnp->cn_namelen, tcnp->cn_cred,
                tcnp->cn_td);

out:
        if (error == 0) {
                nfs_knote(fdvp, NOTE_WRITE);
                nfs_knote(tdvp, NOTE_WRITE);
                nfs_knote(fvp, NOTE_RENAME);
        }
        lwkt_reltoken(&nmp->nm_token);
        if (tdvp == tvp)
                vrele(tdvp);
        else
                vput(tdvp);
        if (tvp)
                vput(tvp);
        vrele(fdvp);
        vrele(fvp);
        /*
         * Kludge: Map ENOENT => 0 assuming that it is a reply to a retry.
         */
        if (error == ENOENT)
                error = 0;
        return (error);
}

/*
 * nfs file rename rpc called from nfs_remove() above
 */
static int
nfs_renameit(struct vnode *sdvp, struct componentname *scnp,
             struct sillyrename *sp)
{
        return (nfs_renamerpc(sdvp, scnp->cn_nameptr, scnp->cn_namelen,
                sdvp, sp->s_name, sp->s_namlen, scnp->cn_cred, scnp->cn_td));
}

/*
 * Do an nfs rename rpc. Called from nfs_rename() and nfs_renameit().
 */
static int
nfs_renamerpc(struct vnode *fdvp, const char *fnameptr, int fnamelen,
              struct vnode *tdvp, const char *tnameptr, int tnamelen,
              struct ucred *cred, struct thread *td)
{
        int error = 0, fwccflag = NFSV3_WCCRATTR, twccflag = NFSV3_WCCRATTR;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(fdvp);

        nfsstats.rpccnt[NFSPROC_RENAME]++;
        nfsm_reqhead(&info, fdvp, NFSPROC_RENAME,
                    (NFSX_FH(info.v3) + NFSX_UNSIGNED)*2 +
                    nfsm_rndup(fnamelen) + nfsm_rndup(tnamelen));
        ERROROUT(nfsm_fhtom(&info, fdvp));
        ERROROUT(nfsm_strtom(&info, fnameptr, fnamelen, NFS_MAXNAMLEN));
        ERROROUT(nfsm_fhtom(&info, tdvp));
        ERROROUT(nfsm_strtom(&info, tnameptr, tnamelen, NFS_MAXNAMLEN));
        NEGKEEPOUT(nfsm_request(&info, fdvp, NFSPROC_RENAME, td, cred, &error));
        if (info.v3) {
                ERROROUT(nfsm_wcc_data(&info, fdvp, &fwccflag));
                ERROROUT(nfsm_wcc_data(&info, tdvp, &twccflag));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        VTONFS(fdvp)->n_flag |= NLMODIFIED;
        VTONFS(tdvp)->n_flag |= NLMODIFIED;
        if (!fwccflag)
                VTONFS(fdvp)->n_attrstamp = 0;
        if (!twccflag)
                VTONFS(tdvp)->n_attrstamp = 0;
        return (error);
}

/*
 * nfs hard link create call
 *
 * nfs_link(struct vnode *a_tdvp, struct vnode *a_vp,
 *          struct componentname *a_cnp)
 */
static int
nfs_link(struct vop_old_link_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *tdvp = ap->a_tdvp;
        struct nfsmount *nmp = VFSTONFS(tdvp->v_mount);
        struct componentname *cnp = ap->a_cnp;
        int error = 0, wccflag = NFSV3_WCCRATTR, attrflag = 0;
        struct nfsm_info info;

        if (vp->v_mount != tdvp->v_mount) {
                return (EXDEV);
        }
        lwkt_gettoken(&nmp->nm_token);

        /*
         * The attribute cache may get out of sync with the server on link.
         * Pushing writes to the server before handle was inherited from
         * long long ago and it is unclear if we still need to do this.
         * Defaults to off.
         */
        if (nfs_flush_on_hlink)
                VOP_FSYNC(vp, MNT_WAIT, 0);

        info.mrep = NULL;
        info.v3 = NFS_ISV3(vp);

        nfsstats.rpccnt[NFSPROC_LINK]++;
        nfsm_reqhead(&info, vp, NFSPROC_LINK,
                     NFSX_FH(info.v3) * 2 + NFSX_UNSIGNED +
                     nfsm_rndup(cnp->cn_namelen));
        ERROROUT(nfsm_fhtom(&info, vp));
        ERROROUT(nfsm_fhtom(&info, tdvp));
        ERROROUT(nfsm_strtom(&info, cnp->cn_nameptr, cnp->cn_namelen,
                             NFS_MAXNAMLEN));
        NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_LINK, cnp->cn_td,
                                cnp->cn_cred, &error));
        if (info.v3) {
                ERROROUT(nfsm_postop_attr(&info, vp, &attrflag,
                                         NFS_LATTR_NOSHRINK));
                ERROROUT(nfsm_wcc_data(&info, tdvp, &wccflag));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        VTONFS(tdvp)->n_flag |= NLMODIFIED;
        if (!attrflag)
                VTONFS(vp)->n_attrstamp = 0;
        if (!wccflag)
                VTONFS(tdvp)->n_attrstamp = 0;
        /*
         * Kludge: Map EEXIST => 0 assuming that it is a reply to a retry.
         */
        if (error == EEXIST)
                error = 0;
        lwkt_reltoken(&nmp->nm_token);
        if (error == 0) {
                nfs_knote(vp, NOTE_LINK);
                nfs_knote(tdvp, NOTE_WRITE);
        }

        return (error);
}

/*
 * nfs symbolic link create call
 *
 * nfs_symlink(struct vnode *a_dvp, struct vnode **a_vpp,
 *              struct componentname *a_cnp, struct vattr *a_vap,
 *              char *a_target)
 */
static int
nfs_symlink(struct vop_old_symlink_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct vattr *vap = ap->a_vap;
        struct nfsmount *nmp = VFSTONFS(dvp->v_mount);
        struct componentname *cnp = ap->a_cnp;
        struct nfsv2_sattr *sp;
        int slen, error = 0, wccflag = NFSV3_WCCRATTR, gotvp;
        struct vnode *newvp = NULL;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);
        lwkt_gettoken(&nmp->nm_token);

        nfsstats.rpccnt[NFSPROC_SYMLINK]++;
        slen = strlen(ap->a_target);
        nfsm_reqhead(&info, dvp, NFSPROC_SYMLINK,
                     NFSX_FH(info.v3) + 2*NFSX_UNSIGNED +
                     nfsm_rndup(cnp->cn_namelen) +
                     nfsm_rndup(slen) + NFSX_SATTR(info.v3));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, cnp->cn_nameptr, cnp->cn_namelen,
                             NFS_MAXNAMLEN));
        if (info.v3) {
                nfsm_v3attrbuild(&info, vap, FALSE);
        }
        ERROROUT(nfsm_strtom(&info, ap->a_target, slen, NFS_MAXPATHLEN));
        if (info.v3 == 0) {
                sp = nfsm_build(&info, NFSX_V2SATTR);
                sp->sa_mode = vtonfsv2_mode(VLNK, vap->va_mode);
                sp->sa_uid = nfs_xdrneg1;
                sp->sa_gid = nfs_xdrneg1;
                sp->sa_size = nfs_xdrneg1;
                txdr_nfsv2time(&vap->va_atime, &sp->sa_atime);
                txdr_nfsv2time(&vap->va_mtime, &sp->sa_mtime);
        }

        /*
         * Issue the NFS request and get the rpc response.
         *
         * Only NFSv3 responses returning an error of 0 actually return
         * a file handle that can be converted into newvp without having
         * to do an extra lookup rpc.
         */
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_SYMLINK, cnp->cn_td,
                                cnp->cn_cred, &error));
        if (info.v3) {
                if (error == 0) {
                       ERROROUT(nfsm_mtofh(&info, dvp, &newvp, &gotvp));
                }
                ERROROUT(nfsm_wcc_data(&info, dvp, &wccflag));
        }

        /*
         * out code jumps -> here, mrep is also freed.
         */

        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:

        /*
         * If we get an EEXIST error, silently convert it to no-error
         * in case of an NFS retry.
         */
        if (error == EEXIST)
                error = 0;

        /*
         * If we do not have (or no longer have) an error, and we could
         * not extract the newvp from the response due to the request being
         * NFSv2 or the error being EEXIST.  We have to do a lookup in order
         * to obtain a newvp to return.  
         */
        if (error == 0 && newvp == NULL) {
                struct nfsnode *np = NULL;

                error = nfs_lookitup(dvp, cnp->cn_nameptr, cnp->cn_namelen,
                                     cnp->cn_cred, cnp->cn_td, &np);
                if (!error)
                        newvp = NFSTOV(np);
        }
        if (error) {
                if (newvp)
                        vput(newvp);
        } else {
                *ap->a_vpp = newvp;
        }
        VTONFS(dvp)->n_flag |= NLMODIFIED;
        if (!wccflag)
                VTONFS(dvp)->n_attrstamp = 0;
        if (error == 0 && *ap->a_vpp)
                nfs_knote(*ap->a_vpp, NOTE_WRITE);
        lwkt_reltoken(&nmp->nm_token);

        return (error);
}

/*
 * nfs make dir call
 *
 * nfs_mkdir(struct vnode *a_dvp, struct vnode **a_vpp,
 *           struct componentname *a_cnp, struct vattr *a_vap)
 */
static int
nfs_mkdir(struct vop_old_mkdir_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct vattr *vap = ap->a_vap;
        struct nfsmount *nmp = VFSTONFS(dvp->v_mount);
        struct componentname *cnp = ap->a_cnp;
        struct nfsv2_sattr *sp;
        struct nfsnode *np = NULL;
        struct vnode *newvp = NULL;
        struct vattr vattr;
        int error = 0, wccflag = NFSV3_WCCRATTR;
        int gotvp = 0;
        int len;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);
        lwkt_gettoken(&nmp->nm_token);

        if ((error = VOP_GETATTR(dvp, &vattr)) != 0) {
                lwkt_reltoken(&nmp->nm_token);
                return (error);
        }
        len = cnp->cn_namelen;
        nfsstats.rpccnt[NFSPROC_MKDIR]++;
        nfsm_reqhead(&info, dvp, NFSPROC_MKDIR,
                     NFSX_FH(info.v3) + NFSX_UNSIGNED +
                     nfsm_rndup(len) + NFSX_SATTR(info.v3));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, cnp->cn_nameptr, len, NFS_MAXNAMLEN));
        if (info.v3) {
                nfsm_v3attrbuild(&info, vap, FALSE);
        } else {
                sp = nfsm_build(&info, NFSX_V2SATTR);
                sp->sa_mode = vtonfsv2_mode(VDIR, vap->va_mode);
                sp->sa_uid = nfs_xdrneg1;
                sp->sa_gid = nfs_xdrneg1;
                sp->sa_size = nfs_xdrneg1;
                txdr_nfsv2time(&vap->va_atime, &sp->sa_atime);
                txdr_nfsv2time(&vap->va_mtime, &sp->sa_mtime);
        }
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_MKDIR, cnp->cn_td,
                    cnp->cn_cred, &error));
        if (error == 0) {
                ERROROUT(nfsm_mtofh(&info, dvp, &newvp, &gotvp));
        }
        if (info.v3) {
                ERROROUT(nfsm_wcc_data(&info, dvp, &wccflag));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        VTONFS(dvp)->n_flag |= NLMODIFIED;
        if (!wccflag)
                VTONFS(dvp)->n_attrstamp = 0;
        /*
         * Kludge: Map EEXIST => 0 assuming that you have a reply to a retry
         * if we can succeed in looking up the directory.
         */
        if (error == EEXIST || (!error && !gotvp)) {
                if (newvp) {
                        vrele(newvp);
                        newvp = NULL;
                }
                error = nfs_lookitup(dvp, cnp->cn_nameptr, len, cnp->cn_cred,
                        cnp->cn_td, &np);
                if (!error) {
                        newvp = NFSTOV(np);
                        if (newvp->v_type != VDIR)
                                error = EEXIST;
                }
        }
        if (error) {
                if (newvp)
                        vrele(newvp);
        } else {
                nfs_knote(dvp, NOTE_WRITE | NOTE_LINK);
                *ap->a_vpp = newvp;
        }
        lwkt_reltoken(&nmp->nm_token);
        return (error);
}

/*
 * nfs remove directory call
 *
 * nfs_rmdir(struct vnode *a_dvp, struct vnode *a_vp,
 *           struct componentname *a_cnp)
 */
static int
nfs_rmdir(struct vop_old_rmdir_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct nfsmount *nmp = VFSTONFS(dvp->v_mount);
        struct componentname *cnp = ap->a_cnp;
        int error = 0, wccflag = NFSV3_WCCRATTR;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);

        if (dvp == vp)
                return (EINVAL);

        lwkt_gettoken(&nmp->nm_token);

        nfsstats.rpccnt[NFSPROC_RMDIR]++;
        nfsm_reqhead(&info, dvp, NFSPROC_RMDIR,
                     NFSX_FH(info.v3) + NFSX_UNSIGNED +
                     nfsm_rndup(cnp->cn_namelen));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, cnp->cn_nameptr, cnp->cn_namelen,
                 NFS_MAXNAMLEN));
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_RMDIR, cnp->cn_td,
                                cnp->cn_cred, &error));
        if (info.v3) {
                ERROROUT(nfsm_wcc_data(&info, dvp, &wccflag));
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        VTONFS(dvp)->n_flag |= NLMODIFIED;
        if (!wccflag)
                VTONFS(dvp)->n_attrstamp = 0;
        /*
         * Kludge: Map ENOENT => 0 assuming that you have a reply to a retry.
         */
        if (error == ENOENT)
                error = 0;
        else
                nfs_knote(dvp, NOTE_WRITE | NOTE_LINK);
        lwkt_reltoken(&nmp->nm_token);

        return (error);
}

/*
 * nfs readdir call
 *
 * nfs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
 */
static int
nfs_readdir(struct vop_readdir_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        struct uio *uio = ap->a_uio;
        int tresid, error;
        struct vattr vattr;

        if (vp->v_type != VDIR)
                return (EPERM);

        error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM);
        if (error)
                return (error);

        lwkt_gettoken(&nmp->nm_token);

        /*
         * If we have a valid EOF offset cache we must call VOP_GETATTR()
         * and then check that is still valid, or if this is an NQNFS mount
         * we call NQNFS_CKCACHEABLE() instead of VOP_GETATTR().  Note that
         * VOP_GETATTR() does not necessarily go to the wire.
         */
        if (np->n_direofoffset > 0 && uio->uio_offset >= np->n_direofoffset &&
            (np->n_flag & (NLMODIFIED|NRMODIFIED)) == 0) {
                if (VOP_GETATTR(vp, &vattr) == 0 &&
                    (np->n_flag & (NLMODIFIED|NRMODIFIED)) == 0
                ) {
                        nfsstats.direofcache_hits++;
                        goto done;
                }
        }

        /*
         * Call nfs_bioread() to do the real work.  nfs_bioread() does its
         * own cache coherency checks so we do not have to.
         */
        tresid = uio->uio_resid;
        error = nfs_bioread(vp, uio, 0);

        if (!error && uio->uio_resid == tresid)
                nfsstats.direofcache_misses++;
done:
        lwkt_reltoken(&nmp->nm_token);
        vn_unlock(vp);

        return (error);
}

/*
 * Readdir rpc call.  nfs_bioread->nfs_doio->nfs_readdirrpc.
 *
 * Note that for directories, nfs_bioread maintains the underlying nfs-centric
 * offset/block and converts the nfs formatted directory entries for userland
 * consumption as well as deals with offsets into the middle of blocks.
 * nfs_doio only deals with logical blocks.  In particular, uio_offset will
 * be block-bounded.  It must convert to cookies for the actual RPC.
 */
int
nfs_readdirrpc_uio(struct vnode *vp, struct uio *uiop)
{
        int len, left;
        struct nfs_dirent *dp = NULL;
        u_int32_t *tl;
        nfsuint64 *cookiep;
        caddr_t cp;
        nfsuint64 cookie;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        struct nfsnode *dnp = VTONFS(vp);
        u_quad_t fileno;
        int error = 0, tlen, more_dirs = 1, blksiz = 0, bigenough = 1;
        int attrflag;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(vp);

#ifndef DIAGNOSTIC
        if (uiop->uio_iovcnt != 1 || (uiop->uio_offset & (DIRBLKSIZ - 1)) ||
                (uiop->uio_resid & (DIRBLKSIZ - 1)))
                panic("nfs readdirrpc bad uio");
#endif

        /*
         * If there is no cookie, assume directory was stale.
         */
        cookiep = nfs_getcookie(dnp, uiop->uio_offset, 0);
        if (cookiep)
                cookie = *cookiep;
        else
                return (NFSERR_BAD_COOKIE);
        /*
         * Loop around doing readdir rpc's of size nm_readdirsize
         * truncated to a multiple of DIRBLKSIZ.
         * The stopping criteria is EOF or buffer full.
         */
        while (more_dirs && bigenough) {
                nfsstats.rpccnt[NFSPROC_READDIR]++;
                nfsm_reqhead(&info, vp, NFSPROC_READDIR,
                             NFSX_FH(info.v3) + NFSX_READDIR(info.v3));
                ERROROUT(nfsm_fhtom(&info, vp));
                if (info.v3) {
                        tl = nfsm_build(&info, 5 * NFSX_UNSIGNED);
                        *tl++ = cookie.nfsuquad[0];
                        *tl++ = cookie.nfsuquad[1];
                        *tl++ = dnp->n_cookieverf.nfsuquad[0];
                        *tl++ = dnp->n_cookieverf.nfsuquad[1];
                } else {
                        /*
                         * WARNING!  HAMMER DIRECTORIES WILL NOT WORK WELL
                         * WITH NFSv2!!!  There's nothing I can really do
                         * about it other than to hope the server supports
                         * rdirplus w/NFSv2.
                         */
                        tl = nfsm_build(&info, 2 * NFSX_UNSIGNED);
                        *tl++ = cookie.nfsuquad[0];
                }
                *tl = txdr_unsigned(nmp->nm_readdirsize);
                NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_READDIR,
                                        uiop->uio_td,
                                        nfs_vpcred(vp, ND_READ), &error));
                if (info.v3) {
                        ERROROUT(nfsm_postop_attr(&info, vp, &attrflag,
                                                  NFS_LATTR_NOSHRINK));
                        NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
                        dnp->n_cookieverf.nfsuquad[0] = *tl++;
                        dnp->n_cookieverf.nfsuquad[1] = *tl;
                }
                NULLOUT(tl = nfsm_dissect(&info, NFSX_UNSIGNED));
                more_dirs = fxdr_unsigned(int, *tl);
        
                /* loop thru the dir entries, converting them to std form */
                while (more_dirs && bigenough) {
                        if (info.v3) {
                                NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
                                fileno = fxdr_hyper(tl);
                                len = fxdr_unsigned(int, *(tl + 2));
                        } else {
                                NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
                                fileno = fxdr_unsigned(u_quad_t, *tl++);
                                len = fxdr_unsigned(int, *tl);
                        }
                        if (len <= 0 || len > NFS_MAXNAMLEN) {
                                error = EBADRPC;
                                m_freem(info.mrep);
                                info.mrep = NULL;
                                goto nfsmout;
                        }

                        /*
                         * len is the number of bytes in the path element
                         * name, not including the \0 termination.
                         *
                         * tlen is the number of bytes w have to reserve for
                         * the path element name.
                         */
                        tlen = nfsm_rndup(len);
                        if (tlen == len)
                                tlen += 4;      /* To ensure null termination */

                        /*
                         * If the entry would cross a DIRBLKSIZ boundary, 
                         * extend the previous nfs_dirent to cover the
                         * remaining space.
                         */
                        left = DIRBLKSIZ - blksiz;
                        if ((tlen + sizeof(struct nfs_dirent)) > left) {
                                dp->nfs_reclen += left;
                                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + left;
                                uiop->uio_iov->iov_len -= left;
                                uiop->uio_offset += left;
                                uiop->uio_resid -= left;
                                blksiz = 0;
                        }
                        if ((tlen + sizeof(struct nfs_dirent)) > uiop->uio_resid)
                                bigenough = 0;
                        if (bigenough) {
                                dp = (struct nfs_dirent *)uiop->uio_iov->iov_base;
                                dp->nfs_ino = fileno;
                                dp->nfs_namlen = len;
                                dp->nfs_reclen = tlen + sizeof(struct nfs_dirent);
                                dp->nfs_type = DT_UNKNOWN;
                                blksiz += dp->nfs_reclen;
                                if (blksiz == DIRBLKSIZ)
                                        blksiz = 0;
                                uiop->uio_offset += sizeof(struct nfs_dirent);
                                uiop->uio_resid -= sizeof(struct nfs_dirent);
                                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + sizeof(struct nfs_dirent);
                                uiop->uio_iov->iov_len -= sizeof(struct nfs_dirent);
                                ERROROUT(nfsm_mtouio(&info, uiop, len));

                                /*
                                 * The uiop has advanced by nfs_dirent + len
                                 * but really needs to advance by
                                 * nfs_dirent + tlen
                                 */
                                cp = uiop->uio_iov->iov_base;
                                tlen -= len;
                                *cp = '\0';     /* null terminate */
                                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + tlen;
                                uiop->uio_iov->iov_len -= tlen;
                                uiop->uio_offset += tlen;
                                uiop->uio_resid -= tlen;
                        } else {
                                /*
                                 * NFS strings must be rounded up (nfsm_myouio
                                 * handled that in the bigenough case).
                                 */
                                ERROROUT(nfsm_adv(&info, nfsm_rndup(len)));
                        }
                        if (info.v3) {
                                NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
                        } else {
                                NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
                        }

                        /*
                         * If we were able to accomodate the last entry,
                         * get the cookie for the next one.  Otherwise
                         * hold-over the cookie for the one we were not
                         * able to accomodate.
                         */
                        if (bigenough) {
                                cookie.nfsuquad[0] = *tl++;
                                if (info.v3)
                                        cookie.nfsuquad[1] = *tl++;
                        } else if (info.v3) {
                                tl += 2;
                        } else {
                                tl++;
                        }
                        more_dirs = fxdr_unsigned(int, *tl);
                }
                /*
                 * If at end of rpc data, get the eof boolean
                 */
                if (!more_dirs) {
                        NULLOUT(tl = nfsm_dissect(&info, NFSX_UNSIGNED));
                        more_dirs = (fxdr_unsigned(int, *tl) == 0);
                }
                m_freem(info.mrep);
                info.mrep = NULL;
        }
        /*
         * Fill last record, iff any, out to a multiple of DIRBLKSIZ
         * by increasing d_reclen for the last record.
         */
        if (blksiz > 0) {
                left = DIRBLKSIZ - blksiz;
                dp->nfs_reclen += left;
                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + left;
                uiop->uio_iov->iov_len -= left;
                uiop->uio_offset += left;
                uiop->uio_resid -= left;
        }

        if (bigenough) {
                /*
                 * We hit the end of the directory, update direofoffset.
                 */
                dnp->n_direofoffset = uiop->uio_offset;
        } else {
                /*
                 * There is more to go, insert the link cookie so the
                 * next block can be read.
                 */
                if (uiop->uio_resid > 0)
                        kprintf("EEK! readdirrpc resid > 0\n");
                cookiep = nfs_getcookie(dnp, uiop->uio_offset, 1);
                *cookiep = cookie;
        }
nfsmout:
        return (error);
}

/*
 * NFS V3 readdir plus RPC. Used in place of nfs_readdirrpc().
 */
int
nfs_readdirplusrpc_uio(struct vnode *vp, struct uio *uiop)
{
        int len, left;
        struct nfs_dirent *dp;
        u_int32_t *tl;
        struct vnode *newvp;
        nfsuint64 *cookiep;
        caddr_t dpossav1, dpossav2;
        caddr_t cp;
        struct mbuf *mdsav1, *mdsav2;
        nfsuint64 cookie;
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        struct nfsnode *dnp = VTONFS(vp), *np;
        nfsfh_t *fhp;
        u_quad_t fileno;
        int error = 0, tlen, more_dirs = 1, blksiz = 0, doit, bigenough = 1, i;
        int attrflag, fhsize;
        struct nchandle nch;
        struct nchandle dnch;
        struct nlcomponent nlc;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = 1;

#ifndef nolint
        dp = NULL;
#endif
#ifndef DIAGNOSTIC
        if (uiop->uio_iovcnt != 1 || (uiop->uio_offset & (DIRBLKSIZ - 1)) ||
                (uiop->uio_resid & (DIRBLKSIZ - 1)))
                panic("nfs readdirplusrpc bad uio");
#endif
        /*
         * Obtain the namecache record for the directory so we have something
         * to use as a basis for creating the entries.  This function will
         * return a held (but not locked) ncp.  The ncp may be disconnected
         * from the tree and cannot be used for upward traversals, and the
         * ncp may be unnamed.  Note that other unrelated operations may 
         * cause the ncp to be named at any time.
         *
         * We have to lock the ncp to prevent a lock order reversal when
         * rdirplus does nlookups of the children, because the vnode is
         * locked and has to stay that way.
         */
        cache_fromdvp(vp, NULL, 0, &dnch);
        bzero(&nlc, sizeof(nlc));
        newvp = NULLVP;

        /*
         * If there is no cookie, assume directory was stale.
         */
        cookiep = nfs_getcookie(dnp, uiop->uio_offset, 0);
        if (cookiep) {
                cookie = *cookiep;
        } else {
                if (dnch.ncp)
                        cache_drop(&dnch);
                return (NFSERR_BAD_COOKIE);
        }

        /*
         * Loop around doing readdir rpc's of size nm_readdirsize
         * truncated to a multiple of DIRBLKSIZ.
         * The stopping criteria is EOF or buffer full.
         */
        while (more_dirs && bigenough) {
                nfsstats.rpccnt[NFSPROC_READDIRPLUS]++;
                nfsm_reqhead(&info, vp, NFSPROC_READDIRPLUS,
                             NFSX_FH(info.v3) + 6 * NFSX_UNSIGNED);
                ERROROUT(nfsm_fhtom(&info, vp));
                tl = nfsm_build(&info, 6 * NFSX_UNSIGNED);
                *tl++ = cookie.nfsuquad[0];
                *tl++ = cookie.nfsuquad[1];
                *tl++ = dnp->n_cookieverf.nfsuquad[0];
                *tl++ = dnp->n_cookieverf.nfsuquad[1];
                *tl++ = txdr_unsigned(nmp->nm_readdirsize);
                *tl = txdr_unsigned(nmp->nm_rsize);
                NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_READDIRPLUS,
                                        uiop->uio_td,
                                        nfs_vpcred(vp, ND_READ), &error));
                ERROROUT(nfsm_postop_attr(&info, vp, &attrflag,
                                          NFS_LATTR_NOSHRINK));
                NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
                dnp->n_cookieverf.nfsuquad[0] = *tl++;
                dnp->n_cookieverf.nfsuquad[1] = *tl++;
                more_dirs = fxdr_unsigned(int, *tl);

                /* loop thru the dir entries, doctoring them to 4bsd form */
                while (more_dirs && bigenough) {
                        NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
                        fileno = fxdr_hyper(tl);
                        len = fxdr_unsigned(int, *(tl + 2));
                        if (len <= 0 || len > NFS_MAXNAMLEN) {
                                error = EBADRPC;
                                m_freem(info.mrep);
                                info.mrep = NULL;
                                goto nfsmout;
                        }
                        tlen = nfsm_rndup(len);
                        if (tlen == len)
                                tlen += 4;      /* To ensure null termination*/
                        left = DIRBLKSIZ - blksiz;
                        if ((tlen + sizeof(struct nfs_dirent)) > left) {
                                dp->nfs_reclen += left;
                                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + left;
                                uiop->uio_iov->iov_len -= left;
                                uiop->uio_offset += left;
                                uiop->uio_resid -= left;
                                blksiz = 0;
                        }
                        if ((tlen + sizeof(struct nfs_dirent)) > uiop->uio_resid)
                                bigenough = 0;
                        if (bigenough) {
                                dp = (struct nfs_dirent *)uiop->uio_iov->iov_base;
                                dp->nfs_ino = fileno;
                                dp->nfs_namlen = len;
                                dp->nfs_reclen = tlen + sizeof(struct nfs_dirent);
                                dp->nfs_type = DT_UNKNOWN;
                                blksiz += dp->nfs_reclen;
                                if (blksiz == DIRBLKSIZ)
                                        blksiz = 0;
                                uiop->uio_offset += sizeof(struct nfs_dirent);
                                uiop->uio_resid -= sizeof(struct nfs_dirent);
                                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + sizeof(struct nfs_dirent);
                                uiop->uio_iov->iov_len -= sizeof(struct nfs_dirent);
                                nlc.nlc_nameptr = uiop->uio_iov->iov_base;
                                nlc.nlc_namelen = len;
                                ERROROUT(nfsm_mtouio(&info, uiop, len));
                                cp = uiop->uio_iov->iov_base;
                                tlen -= len;
                                *cp = '\0';
                                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + tlen;
                                uiop->uio_iov->iov_len -= tlen;
                                uiop->uio_offset += tlen;
                                uiop->uio_resid -= tlen;
                        } else {
                                ERROROUT(nfsm_adv(&info, nfsm_rndup(len)));
                        }
                        NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
                        if (bigenough) {
                                cookie.nfsuquad[0] = *tl++;
                                cookie.nfsuquad[1] = *tl++;
                        } else {
                                tl += 2;
                        }

                        /*
                         * Since the attributes are before the file handle
                         * (sigh), we must skip over the attributes and then
                         * come back and get them.
                         */
                        attrflag = fxdr_unsigned(int, *tl);
                        if (attrflag) {
                            dpossav1 = info.dpos;
                            mdsav1 = info.md;
                            ERROROUT(nfsm_adv(&info, NFSX_V3FATTR));
                            NULLOUT(tl = nfsm_dissect(&info, NFSX_UNSIGNED));
                            doit = fxdr_unsigned(int, *tl);
                            if (doit) {
                                NEGATIVEOUT(fhsize = nfsm_getfh(&info, &fhp));
                            }
                            if (doit && bigenough && !nlcdegenerate(&nlc) &&
                                !NFS_CMPFH(dnp, fhp, fhsize)
                            ) {
                                if (dnch.ncp) {
#if 0
                                    kprintf("NFS/READDIRPLUS, ENTER %*.*s\n",
                                        nlc.nlc_namelen, nlc.nlc_namelen,
                                        nlc.nlc_nameptr);
#endif
                                    /*
                                     * This is a bit hokey but there isn't
                                     * much we can do about it.  We can't
                                     * hold the directory vp locked while
                                     * doing lookups and gets.
                                     */
                                    nch = cache_nlookup_nonblock(&dnch, &nlc);
                                    if (nch.ncp == NULL)
                                        goto rdfail;
                                    cache_setunresolved(&nch);
                                    error = nfs_nget_nonblock(vp->v_mount, fhp,
                                                              fhsize, &np,
                                                              NULL);
                                    if (error) {
                                        cache_put(&nch);
                                        goto rdfail;
                                    }
                                    newvp = NFSTOV(np);
                                    dpossav2 = info.dpos;
                                    info.dpos = dpossav1;
                                    mdsav2 = info.md;
                                    info.md = mdsav1;
                                    ERROROUT(nfsm_loadattr(&info, newvp, NULL));
                                    info.dpos = dpossav2;
                                    info.md = mdsav2;
                                    dp->nfs_type =
                                            IFTODT(VTTOIF(np->n_vattr.va_type));
                                    nfs_cache_setvp(&nch, newvp,
                                                    nfspos_cache_timeout);
                                    vput(newvp);
                                    newvp = NULLVP;
                                    cache_put(&nch);
                                } else {
rdfail:
                                    ;
#if 0
                                    kprintf("Warning: NFS/rddirplus, "
                                            "UNABLE TO ENTER %*.*s\n",
                                        nlc.nlc_namelen, nlc.nlc_namelen,
                                        nlc.nlc_nameptr);
#endif
                                }
                            }
                        } else {
                            /* Just skip over the file handle */
                            NULLOUT(tl = nfsm_dissect(&info, NFSX_UNSIGNED));
                            i = fxdr_unsigned(int, *tl);
                            ERROROUT(nfsm_adv(&info, nfsm_rndup(i)));
                        }
                        NULLOUT(tl = nfsm_dissect(&info, NFSX_UNSIGNED));
                        more_dirs = fxdr_unsigned(int, *tl);
                }
                /*
                 * If at end of rpc data, get the eof boolean
                 */
                if (!more_dirs) {
                        NULLOUT(tl = nfsm_dissect(&info, NFSX_UNSIGNED));
                        more_dirs = (fxdr_unsigned(int, *tl) == 0);
                }
                m_freem(info.mrep);
                info.mrep = NULL;
        }
        /*
         * Fill last record, iff any, out to a multiple of DIRBLKSIZ
         * by increasing d_reclen for the last record.
         */
        if (blksiz > 0) {
                left = DIRBLKSIZ - blksiz;
                dp->nfs_reclen += left;
                uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + left;
                uiop->uio_iov->iov_len -= left;
                uiop->uio_offset += left;
                uiop->uio_resid -= left;
        }

        /*
         * We are now either at the end of the directory or have filled the
         * block.
         */
        if (bigenough) {
                dnp->n_direofoffset = uiop->uio_offset;
        } else {
                if (uiop->uio_resid > 0)
                        kprintf("EEK! readdirplusrpc resid > 0\n");
                cookiep = nfs_getcookie(dnp, uiop->uio_offset, 1);
                *cookiep = cookie;
        }
nfsmout:
        if (newvp != NULLVP) {
                if (newvp == vp)
                        vrele(newvp);
                else
                        vput(newvp);
                newvp = NULLVP;
        }
        if (dnch.ncp)
                cache_drop(&dnch);
        return (error);
}

/*
 * Silly rename. To make the NFS filesystem that is stateless look a little
 * more like the "ufs" a remove of an active vnode is translated to a rename
 * to a funny looking filename that is removed by nfs_inactive on the
 * nfsnode. There is the potential for another process on a different client
 * to create the same funny name between the nfs_lookitup() fails and the
 * nfs_rename() completes, but...
 */
static int
nfs_sillyrename(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
{
        struct sillyrename *sp;
        struct nfsnode *np;
        int error;

        /*
         * Force finalization so the VOP_INACTIVE() call is not delayed.
         * This prevents cred structures from building up in nfsnodes
         * for deleted files.
         */
        atomic_set_int(&vp->v_refcnt, VREF_FINALIZE);
        np = VTONFS(vp);
        np->n_flag |= NREMOVED;

        /*
         * We previously purged dvp instead of vp.  I don't know why, it
         * completely destroys performance.  We can't do it anyway with the
         * new VFS API since we would be breaking the namecache topology.
         */
        cache_purge(vp);        /* XXX */
#ifndef DIAGNOSTIC
        if (vp->v_type == VDIR)
                panic("nfs: sillyrename dir");
#endif
        sp = kmalloc(sizeof(struct sillyrename), M_NFSREQ, M_WAITOK);
        sp->s_cred = crdup(cnp->cn_cred);
        sp->s_dvp = dvp;
        vref(dvp);

        /* Fudge together a funny name */
        sp->s_namlen = ksprintf(sp->s_name, ".nfsA%08x4.4",
                                (int)(intptr_t)cnp->cn_td);

        /* Try lookitups until we get one that isn't there */
        while (nfs_lookitup(dvp, sp->s_name, sp->s_namlen, sp->s_cred,
                cnp->cn_td, NULL) == 0) {
                sp->s_name[4]++;
                if (sp->s_name[4] > 'z') {
                        error = EINVAL;
                        goto bad;
                }
        }
        error = nfs_renameit(dvp, cnp, sp);
        if (error)
                goto bad;
        error = nfs_lookitup(dvp, sp->s_name, sp->s_namlen, sp->s_cred,
                cnp->cn_td, &np);
        np->n_sillyrename = sp;
        return (0);
bad:
        vrele(sp->s_dvp);
        crfree(sp->s_cred);
        kfree((caddr_t)sp, M_NFSREQ);

        return (error);
}

/*
 * Look up a file name and optionally either update the file handle or
 * allocate an nfsnode, depending on the value of npp.
 * npp == NULL  --> just do the lookup
 * *npp == NULL --> allocate a new nfsnode and make sure attributes are
 *                      handled too
 * *npp != NULL --> update the file handle in the vnode
 */
static int
nfs_lookitup(struct vnode *dvp, const char *name, int len, struct ucred *cred,
             struct thread *td, struct nfsnode **npp)
{
        struct vnode *newvp = NULL;
        struct nfsnode *np, *dnp = VTONFS(dvp);
        int error = 0, fhlen, attrflag;
        nfsfh_t *nfhp;
        struct nfsm_info info;

        info.mrep = NULL;
        info.v3 = NFS_ISV3(dvp);

        nfsstats.rpccnt[NFSPROC_LOOKUP]++;
        nfsm_reqhead(&info, dvp, NFSPROC_LOOKUP,
                     NFSX_FH(info.v3) + NFSX_UNSIGNED + nfsm_rndup(len));
        ERROROUT(nfsm_fhtom(&info, dvp));
        ERROROUT(nfsm_strtom(&info, name, len, NFS_MAXNAMLEN));
        NEGKEEPOUT(nfsm_request(&info, dvp, NFSPROC_LOOKUP, td, cred, &error));
        if (npp && !error) {
                NEGATIVEOUT(fhlen = nfsm_getfh(&info, &nfhp));
                if (*npp) {
                    np = *npp;
                    if (np->n_fhsize > NFS_SMALLFH && fhlen <= NFS_SMALLFH) {
                        kfree((caddr_t)np->n_fhp, M_NFSBIGFH);
                        np->n_fhp = &np->n_fh;
                    } else if (np->n_fhsize <= NFS_SMALLFH && fhlen>NFS_SMALLFH)
                        np->n_fhp =(nfsfh_t *)kmalloc(fhlen,M_NFSBIGFH,M_WAITOK);
                    bcopy((caddr_t)nfhp, (caddr_t)np->n_fhp, fhlen);
                    np->n_fhsize = fhlen;
                    newvp = NFSTOV(np);
                } else if (NFS_CMPFH(dnp, nfhp, fhlen)) {
                    vref(dvp);
                    newvp = dvp;
                } else {
                    error = nfs_nget(dvp->v_mount, nfhp, fhlen, &np, NULL);
                    if (error) {
                        m_freem(info.mrep);
                        info.mrep = NULL;
                        return (error);
                    }
                    newvp = NFSTOV(np);
                }
                if (info.v3) {
                        ERROROUT(nfsm_postop_attr(&info, newvp, &attrflag,
                                                  NFS_LATTR_NOSHRINK));
                        if (!attrflag && *npp == NULL) {
                                m_freem(info.mrep);
                                info.mrep = NULL;
                                if (newvp == dvp)
                                        vrele(newvp);
                                else
                                        vput(newvp);
                                return (ENOENT);
                        }
                } else {
                        ERROROUT(nfsm_loadattr(&info, newvp, NULL));
                }
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        if (npp && *npp == NULL) {
                if (error) {
                        if (newvp) {
                                if (newvp == dvp)
                                        vrele(newvp);
                                else
                                        vput(newvp);
                        }
                } else
                        *npp = np;
        }
        return (error);
}

/*
 * Nfs Version 3 commit rpc
 *
 * We call it 'uio' to distinguish it from 'bio' but there is no real uio
 * involved.
 */
int
nfs_commitrpc_uio(struct vnode *vp, u_quad_t offset, int cnt, struct thread *td)
{
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        int error = 0, wccflag = NFSV3_WCCRATTR;
        struct nfsm_info info;
        u_int32_t *tl;

        info.mrep = NULL;
        info.v3 = 1;
        
        if ((nmp->nm_state & NFSSTA_HASWRITEVERF) == 0)
                return (0);
        nfsstats.rpccnt[NFSPROC_COMMIT]++;
        nfsm_reqhead(&info, vp, NFSPROC_COMMIT, NFSX_FH(1));
        ERROROUT(nfsm_fhtom(&info, vp));
        tl = nfsm_build(&info, 3 * NFSX_UNSIGNED);
        txdr_hyper(offset, tl);
        tl += 2;
        *tl = txdr_unsigned(cnt);
        NEGKEEPOUT(nfsm_request(&info, vp, NFSPROC_COMMIT, td,
                                nfs_vpcred(vp, ND_WRITE), &error));
        ERROROUT(nfsm_wcc_data(&info, vp, &wccflag));
        if (!error) {
                NULLOUT(tl = nfsm_dissect(&info, NFSX_V3WRITEVERF));
                if (bcmp((caddr_t)nmp->nm_verf, (caddr_t)tl,
                        NFSX_V3WRITEVERF)) {
                        bcopy((caddr_t)tl, (caddr_t)nmp->nm_verf,
                                NFSX_V3WRITEVERF);
                        error = NFSERR_STALEWRITEVERF;
                }
        }
        m_freem(info.mrep);
        info.mrep = NULL;
nfsmout:
        return (error);
}

/*
 * Kludge City..
 * - make nfs_bmap() essentially a no-op that does no translation
 * - do nfs_strategy() by doing I/O with nfs_readrpc/nfs_writerpc
 *   (Maybe I could use the process's page mapping, but I was concerned that
 *    Kernel Write might not be enabled and also figured copyout() would do
 *    a lot more work than bcopy() and also it currently happens in the
 *    context of the swapper process (2).
 *
 * nfs_bmap(struct vnode *a_vp, off_t a_loffset,
 *          off_t *a_doffsetp, int *a_runp, int *a_runb)
 */
static int
nfs_bmap(struct vop_bmap_args *ap)
{
        /* no token lock required */
        if (ap->a_doffsetp != NULL)
                *ap->a_doffsetp = ap->a_loffset;
        if (ap->a_runp != NULL)
                *ap->a_runp = 0;
        if (ap->a_runb != NULL)
                *ap->a_runb = 0;
        return (0);
}

/*
 * Strategy routine.
 */
static int
nfs_strategy(struct vop_strategy_args *ap)
{
        struct bio *bio = ap->a_bio;
        struct bio *nbio;
        struct buf *bp __debugvar = bio->bio_buf;
        struct nfsmount *nmp = VFSTONFS(ap->a_vp->v_mount);
        struct thread *td;
        int error;

        KASSERT(bp->b_cmd != BUF_CMD_DONE,
                ("nfs_strategy: buffer %p unexpectedly marked done", bp));
        KASSERT(BUF_LOCKINUSE(bp),
                ("nfs_strategy: buffer %p not locked", bp));

        if (bio->bio_flags & BIO_SYNC)
                td = curthread; /* XXX */
        else
                td = NULL;

        lwkt_gettoken(&nmp->nm_token);

        /*
         * We probably don't need to push an nbio any more since no
         * block conversion is required due to the use of 64 bit byte
         * offsets, but do it anyway.
         *
         * NOTE: When NFS callers itself via this strategy routines and
         *       sets up a synchronous I/O, it expects the I/O to run
         *       synchronously (its bio_done routine just assumes it),
         *       so for now we have to honor the bit.
         */
        nbio = push_bio(bio);
        nbio->bio_offset = bio->bio_offset;
        nbio->bio_flags = bio->bio_flags & BIO_SYNC;

        /*
         * If the op is asynchronous and an i/o daemon is waiting
         * queue the request, wake it up and wait for completion
         * otherwise just do it ourselves.
         */
        if (bio->bio_flags & BIO_SYNC) {
                error = nfs_doio(ap->a_vp, nbio, td);
        } else {
                nfs_asyncio(ap->a_vp, nbio);
                error = 0;
        }
        lwkt_reltoken(&nmp->nm_token);

        return (error);
}

/*
 * fsync vnode op. Just call nfs_flush() with commit == 1.
 *
 * nfs_fsync(struct vnode *a_vp, int a_waitfor)
 */
/* ARGSUSED */
static int
nfs_fsync(struct vop_fsync_args *ap)
{
        struct nfsmount *nmp = VFSTONFS(ap->a_vp->v_mount);
        int error;

        lwkt_gettoken(&nmp->nm_token);

        /*
         * NOTE: Because attributes are set synchronously we currently
         *       do not have to implement vsetisdirty()/vclrisdirty().
         */
        error = nfs_flush(ap->a_vp, ap->a_waitfor, curthread, 1);

        lwkt_reltoken(&nmp->nm_token);

        return error;
}

/*
 * Flush all the blocks associated with a vnode.   Dirty NFS buffers may be
 * in one of two states:  If B_NEEDCOMMIT is clear then the buffer contains
 * new NFS data which needs to be written to the server.  If B_NEEDCOMMIT is
 * set the buffer contains data that has already been written to the server
 * and which now needs a commit RPC.
 *
 * If commit is 0 we only take one pass and only flush buffers containing new
 * dirty data.
 *
 * If commit is 1 we take two passes, issuing a commit RPC in the second
 * pass.
 *
 * If waitfor is MNT_WAIT and commit is 1, we loop as many times as required
 * to completely flush all pending data.
 *
 * Note that the RB_SCAN code properly handles the case where the
 * callback might block and directly or indirectly (another thread) cause
 * the RB tree to change.
 */

#ifndef NFS_COMMITBVECSIZ
#define NFS_COMMITBVECSIZ       16
#endif

struct nfs_flush_info {
        enum { NFI_FLUSHNEW, NFI_COMMIT } mode;
        struct thread *td;
        struct vnode *vp;
        int waitfor;
        int slpflag;
        int slptimeo;
        int loops;
        struct buf *bvary[NFS_COMMITBVECSIZ];
        int bvsize;
        off_t beg_off;
        off_t end_off;
};

static int nfs_flush_bp(struct buf *bp, void *data);
static int nfs_flush_docommit(struct nfs_flush_info *info, int error);

int
nfs_flush(struct vnode *vp, int waitfor, struct thread *td, int commit)
{
        struct nfsnode *np = VTONFS(vp);
        struct nfsmount *nmp = VFSTONFS(vp->v_mount);
        struct nfs_flush_info info;
        int error;

        bzero(&info, sizeof(info));
        info.td = td;
        info.vp = vp;
        info.waitfor = waitfor;
        info.slpflag = (nmp->nm_flag & NFSMNT_INT) ? PCATCH : 0;
        info.loops = 0;
        lwkt_gettoken(&vp->v_token);

        do {
                /*
                 * Flush mode
                 */
                info.mode = NFI_FLUSHNEW;
                error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL, 
                                nfs_flush_bp, &info);

                /*
                 * Take a second pass if committing and no error occured.  
                 * Clean up any left over collection (whether an error 
                 * occurs or not).
                 */
                if (commit && error == 0) {
                        info.mode = NFI_COMMIT;
                        error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL, 
                                        nfs_flush_bp, &info);
                        if (info.bvsize)
                                error = nfs_flush_docommit(&info, error);
                }

                /*
                 * Wait for pending I/O to complete before checking whether
                 * any further dirty buffers exist.
                 */
                while (waitfor == MNT_WAIT &&
                       bio_track_active(&vp->v_track_write)) {
                        error = bio_track_wait(&vp->v_track_write,
                                               info.slpflag, info.slptimeo);
                        if (error) {
                                /*
                                 * We have to be able to break out if this 
                                 * is an 'intr' mount.
                                 */
                                if (nfs_sigintr(nmp, NULL, td)) {
                                        error = -EINTR;
                                        break;
                                }

                                /*
                                 * Since we do not process pending signals,
                                 * once we get a PCATCH our tsleep() will no
                                 * longer sleep, switch to a fixed timeout
                                 * instead.
                                 */
                                if (info.slpflag == PCATCH) {
                                        info.slpflag = 0;
                                        info.slptimeo = 2 * hz;
                                }
                                error = 0;
                        }
                }
                ++info.loops;
                /*
                 * Loop if we are flushing synchronous as well as committing,
                 * and dirty buffers are still present.  Otherwise we might livelock.
                 */
        } while (waitfor == MNT_WAIT && commit && 
                 error == 0 && !RB_EMPTY(&vp->v_rbdirty_tree));

        /*
         * The callbacks have to return a negative error to terminate the
         * RB scan.
         */
        if (error < 0)
                error = -error;

        /*
         * Deal with any error collection
         */
        if (np->n_flag & NWRITEERR) {
                error = np->n_error;
                np->n_flag &= ~NWRITEERR;
        }
        lwkt_reltoken(&vp->v_token);
        return (error);
}

static
int
nfs_flush_bp(struct buf *bp, void *data)
{
        struct nfs_flush_info *info = data;
        int lkflags;
        int error;
        off_t toff;

        error = 0;
        switch(info->mode) {
        case NFI_FLUSHNEW:
                error = BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT);
                if (error && info->loops && info->waitfor == MNT_WAIT) {
                        error = BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT);
                        if (error) {
                                lkflags = LK_EXCLUSIVE | LK_SLEEPFAIL;
                                if (info->slpflag & PCATCH)
                                        lkflags |= LK_PCATCH;
                                atomic_add_int(&bp->b_refs, 1);
                                error = BUF_TIMELOCK(bp, lkflags, "nfsfsync",
                                                     info->slptimeo);
                                atomic_add_int(&bp->b_refs, -1);
                        }
                }

                /*
                 * Ignore locking errors
                 */
                if (error) {
                        error = 0;
                        break;
                }

                /*
                 * The buffer may have changed out from under us, even if
                 * we did not block (MPSAFE).  Check again now that it is
                 * locked.
                 */
                if (bp->b_vp == info->vp &&
                    (bp->b_flags & (B_DELWRI | B_NEEDCOMMIT)) == B_DELWRI) {
                        bremfree(bp);
                        bawrite(bp);
                } else {
                        BUF_UNLOCK(bp);
                }
                break;
        case NFI_COMMIT:
                /*
                 * Only process buffers in need of a commit which we can
                 * immediately lock.  This may prevent a buffer from being
                 * committed, but the normal flush loop will block on the
                 * same buffer so we shouldn't get into an endless loop.
                 */
                if ((bp->b_flags & (B_DELWRI | B_NEEDCOMMIT)) != 
                    (B_DELWRI | B_NEEDCOMMIT)) {
                        break;
                }
                if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
                        break;

                /*
                 * We must recheck after successfully locking the buffer.
                 */
                if (bp->b_vp != info->vp ||
                    (bp->b_flags & (B_DELWRI | B_NEEDCOMMIT)) !=
                    (B_DELWRI | B_NEEDCOMMIT)) {
                        BUF_UNLOCK(bp);
                        break;
                }

                /*
                 * NOTE: storing the bp in the bvary[] basically sets
                 * it up for a commit operation.
                 *
                 * We must call vfs_busy_pages() now so the commit operation
                 * is interlocked with user modifications to memory mapped
                 * pages.  The b_dirtyoff/b_dirtyend range is not correct
                 * until after the pages have been busied.
                 *
                 * Note: to avoid loopback deadlocks, we do not
                 * assign b_runningbufspace.
                 */
                bremfree(bp);
                bp->b_cmd = BUF_CMD_WRITE;
                vfs_busy_pages(bp->b_vp, bp);
                info->bvary[info->bvsize] = bp;
                toff = bp->b_bio2.bio_offset + bp->b_dirtyoff;
                if (info->bvsize == 0 || toff < info->beg_off)
                        info->beg_off = toff;
                toff += (off_t)(bp->b_dirtyend - bp->b_dirtyoff);
                if (info->bvsize == 0 || toff > info->end_off)
                        info->end_off = toff;
                ++info->bvsize;
                if (info->bvsize == NFS_COMMITBVECSIZ) {
                        error = nfs_flush_docommit(info, 0);
                        KKASSERT(info->bvsize == 0);
                }
        }
        return (error);
}

static
int
nfs_flush_docommit(struct nfs_flush_info *info, int error)
{
        struct vnode *vp;
        struct buf *bp;
        off_t bytes;
        int retv;
        int i;

        vp = info->vp;

        if (info->bvsize > 0) {
                /*
                 * Commit data on the server, as required.  Note that
                 * nfs_commit will use the vnode's cred for the commit.
                 * The NFSv3 commit RPC is limited to a 32 bit byte count.
                 */
                bytes = info->end_off - info->beg_off;
                if (bytes > 0x40000000)
                        bytes = 0x40000000;
                if (error) {
                        retv = -error;
                } else {
                        retv = nfs_commitrpc_uio(vp, info->beg_off,
                                                 (int)bytes, info->td);
                        if (retv == NFSERR_STALEWRITEVERF)
                                nfs_clearcommit(vp->v_mount);
                }

                /*
                 * Now, either mark the blocks I/O done or mark the
                 * blocks dirty, depending on whether the commit
                 * succeeded.
                 */
                for (i = 0; i < info->bvsize; ++i) {
                        bp = info->bvary[i];
                        if (retv || (bp->b_flags & B_NEEDCOMMIT) == 0) {
                                /*
                                 * Either an error or the original
                                 * vfs_busy_pages() cleared B_NEEDCOMMIT
                                 * due to finding new dirty VM pages in
                                 * the buffer.
                                 *
                                 * Leave B_DELWRI intact.
                                 */
                                bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
                                vfs_unbusy_pages(bp);
                                bp->b_cmd = BUF_CMD_DONE;
                                bqrelse(bp);
                        } else {
                                /*
                                 * Success, remove B_DELWRI ( bundirty() ).
                                 *
                                 * b_dirtyoff/b_dirtyend seem to be NFS 
                                 * specific.  We should probably move that
                                 * into bundirty(). XXX
                                 *
                                 * We are faking an I/O write, we have to 
                                 * start the transaction in order to
                                 * immediately biodone() it.
                                 */
                                bundirty(bp);
                                bp->b_flags &= ~B_ERROR;
                                bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
                                bp->b_dirtyoff = bp->b_dirtyend = 0;
                                biodone(&bp->b_bio1);
                        }
                }
                info->bvsize = 0;
        }
        return (error);
}

/*
 * NFS advisory byte-level locks.
 * Currently unsupported.
 *
 * nfs_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, struct flock *a_fl,
 *              int a_flags)
 */
static int
nfs_advlock(struct vop_advlock_args *ap)
{
        struct nfsnode *np = VTONFS(ap->a_vp);

        /* no token lock currently required */
        /*
         * The following kludge is to allow diskless support to work
         * until a real NFS lockd is implemented. Basically, just pretend
         * that this is a local lock.
         */
        return (lf_advlock(ap, &(np->n_lockf), np->n_size));
}

/*
 * Print out the contents of an nfsnode.
 *
 * nfs_print(struct vnode *a_vp)
 */
static int
nfs_print(struct vop_print_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);

        kprintf("tag VT_NFS, fileid %lld fsid 0x%x",
                (long long)np->n_vattr.va_fileid, np->n_vattr.va_fsid);
        if (vp->v_type == VFIFO)
                fifo_printinfo(vp);
        kprintf("\n");
        return (0);
}

/*
 * nfs special file access vnode op.
 *
 * nfs_laccess(struct vnode *a_vp, int a_mode, struct ucred *a_cred)
 */
static int
nfs_laccess(struct vop_access_args *ap)
{
        struct nfsmount *nmp = VFSTONFS(ap->a_vp->v_mount);
        struct vattr vattr;
        int error;

        lwkt_gettoken(&nmp->nm_token);
        error = VOP_GETATTR(ap->a_vp, &vattr);
        if (error == 0) {
                error = vop_helper_access(ap, vattr.va_uid, vattr.va_gid, 
                                          vattr.va_mode, 0);
        }
        lwkt_reltoken(&nmp->nm_token);

        return (error);
}

/*
 * Read wrapper for fifos.
 *
 * nfsfifo_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
 *              struct ucred *a_cred)
 */
static int
nfsfifo_read(struct vop_read_args *ap)
{
        struct nfsnode *np = VTONFS(ap->a_vp);

        /* no token access required */
        /*
         * Set access flag.
         */
        np->n_flag |= NACC;
        getnanotime(&np->n_atim);
        return (VOCALL(&fifo_vnode_vops, &ap->a_head));
}

/*
 * Write wrapper for fifos.
 *
 * nfsfifo_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
 *               struct ucred *a_cred)
 */
static int
nfsfifo_write(struct vop_write_args *ap)
{
        struct nfsnode *np = VTONFS(ap->a_vp);

        /* no token access required */
        /*
         * Set update flag.
         */
        np->n_flag |= NUPD;
        getnanotime(&np->n_mtim);
        return (VOCALL(&fifo_vnode_vops, &ap->a_head));
}

/*
 * Close wrapper for fifos.
 *
 * Update the times on the nfsnode then do fifo close.
 *
 * nfsfifo_close(struct vnode *a_vp, int a_fflag)
 */
static int
nfsfifo_close(struct vop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct nfsnode *np = VTONFS(vp);
        struct vattr vattr;
        struct timespec ts;

        /* no token access required */

        vn_lock(vp, LK_UPGRADE | LK_RETRY); /* XXX */
        if (np->n_flag & (NACC | NUPD)) {
                getnanotime(&ts);
                if (np->n_flag & NACC)
                        np->n_atim = ts;
                if (np->n_flag & NUPD)
                        np->n_mtim = ts;
                np->n_flag |= NCHG;
                if (VREFCNT(vp) == 1 &&
                    (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
                        VATTR_NULL(&vattr);
                        if (np->n_flag & NACC)
                                vattr.va_atime = np->n_atim;
                        if (np->n_flag & NUPD)
                                vattr.va_mtime = np->n_mtim;
                        (void)VOP_SETATTR(vp, &vattr, nfs_vpcred(vp, ND_WRITE));
                }
        }
        return (VOCALL(&fifo_vnode_vops, &ap->a_head));
}

/************************************************************************
 *                          KQFILTER OPS                                *
 ************************************************************************/

static void filt_nfsdetach(struct knote *kn);
static int filt_nfsread(struct knote *kn, long hint);
static int filt_nfswrite(struct knote *kn, long hint);
static int filt_nfsvnode(struct knote *kn, long hint);

static struct filterops nfsread_filtops =
        { FILTEROP_ISFD | FILTEROP_MPSAFE,
          NULL, filt_nfsdetach, filt_nfsread };
static struct filterops nfswrite_filtops =
        { FILTEROP_ISFD | FILTEROP_MPSAFE,
          NULL, filt_nfsdetach, filt_nfswrite };
static struct filterops nfsvnode_filtops =
        { FILTEROP_ISFD | FILTEROP_MPSAFE,
          NULL, filt_nfsdetach, filt_nfsvnode };

static int
nfs_kqfilter (struct vop_kqfilter_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct knote *kn = ap->a_kn;

        switch (kn->kn_filter) {
        case EVFILT_READ:
                kn->kn_fop = &nfsread_filtops;
                break;
        case EVFILT_WRITE:
                kn->kn_fop = &nfswrite_filtops;
                break;
        case EVFILT_VNODE:
                kn->kn_fop = &nfsvnode_filtops;
                break;
        default:
                return (EOPNOTSUPP);
        }

        kn->kn_hook = (caddr_t)vp;

        knote_insert(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);

        return(0);
}

static void
filt_nfsdetach(struct knote *kn)
{
        struct vnode *vp = (void *)kn->kn_hook;

        knote_remove(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
}

static int
filt_nfsread(struct knote *kn, long hint)
{
        struct vnode *vp = (void *)kn->kn_hook;
        struct nfsnode *node = VTONFS(vp);
        off_t off;

        if (hint == NOTE_REVOKE) {
                kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
                return(1);
        }

        /*
         * Interlock against MP races when performing this function. XXX
         */
        /* TMPFS_NODE_LOCK_SH(node); */
        off = node->n_size - kn->kn_fp->f_offset;
        kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
        if (kn->kn_sfflags & NOTE_OLDAPI) {
                /* TMPFS_NODE_UNLOCK(node); */
                return(1);
        }
        if (kn->kn_data == 0) {
                kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
        }
        /* TMPFS_NODE_UNLOCK(node); */
        return (kn->kn_data != 0);
}

static int
filt_nfswrite(struct knote *kn, long hint)
{
        if (hint == NOTE_REVOKE)
                kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
        kn->kn_data = 0;
        return (1);
}

static int
filt_nfsvnode(struct knote *kn, long hint)
{
        if (kn->kn_sfflags & hint)
                kn->kn_fflags |= hint;
        if (hint == NOTE_REVOKE) {
                kn->kn_flags |= (EV_EOF | EV_NODATA);
                return (1);
        }
        return (kn->kn_fflags != 0);
}